Physics Combined Science Revision Pack FOUNDATION Date

Science Faculty

Physics Combined Science Revision Pack

FOUNDATION

Date Title completed 03/02/2020 Energy 10/02/2020 Electricity: circuits and symbols 17/02/2020 Exam practice 24/02/2020 Eletricity; in our homes 02/03/2020 Particle model of matter 09/03/2020 Exam practice 16/03/2020 Atomic Strcuture 23/03/2020 Forces; application 30/03/2020 Forces; motion 06/04/2020 Exam practice 13/04/2020 Exam practice 20/04/2020 Waves 27/04/2020 Electromagnetism 04/05/2020 Equations and maths 11/05/2020 Longer answer questions 18/05/2020 Paper 1 revision: 20/05/2020 25/05/2020 Exam practice 01/06/2020 Exam practice 08/06/2020 Paper 2 revision: 15/06/2020

AQA Trilogy: Combined Science

What to expect?

For the exam you will sit 2 papers each 70 minutes long

The topics covered in Paper 1 are;

1. Energy

2. Electricity

3. Particle model of matter

4. Atomic structure

The topics covered in Paper 2 are;

5. Forces

6. Waves

7. Magnetism and electromagnetism

Your total score from Physics will be added to that of Biology and Chemistry and your final

grade a result of the combined.

Expect the paper to cover all information from the above as well as 30% maths, 15%

required practical. Paper 2 will cover some of the content from paper 1 in that you may still

be requried to use the equations from the first 4 topics.

Key tips for the exam

Answer every question

Use key scientific words

Be prepared 30% of the paper will be maths

Use a calculator to answer questions

Look at the units for hints

Write an equation and substitute in numbers

Physics 1: Energy

Energy

check foundation higher triple

A system is an object or group of objects.

There are changes in the way energy is stored when a system changes.

Students should be able to describe all the changes involved in the way energy is stored when a system changes, for common situations. For example: • an object projected upwards • a moving object hitting an obstacle • an object accelerated by a constant force • a vehicle slowing down • bringing water to a boil in an electric kettle.

Throughout this section on Energy students should be able to calculate the changes in energy involved when a system is changed by: • heating • work done by forces • work done when a current flows

use calculations to show how the overall energy in a system is redistributed when the system is changed.

Students should be able to calculate the amount of energy associated with a moving object, a stretched spring and an object raised above ground level.

Students should be able to recall and apply this equation. kinetic energy = 0.5 × mass × speed2

The amount of elastic potential energy stored in a stretched spring can be calculated using the equation: elastic potential energy = 0.5 × spring constant × extension2

The amount of gravitational potential energy gained by an object raised above ground level can be calculated using the equation: g . p . e . = mass × gravitational field strength × height

The amount of energy stored in or released from a system as its temperature changes can be calculated using the equation: change in thermal energy = mass × specific heat capacity × temperature change which is given on the Physics equation sheet.

The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

investigation to determine the specific heat capacity of one or more materials. The investigation will involve linking the decrease of one energy store (or work done) to the increase in temperature and subsequent increase in thermal energy stored.

Power is defined as the rate at which energy is transferred or the rate at which work is done.

Students should be able to recall and apply both equations. power = energy transferred/time power = work done/time

An energy transfer of 1 joule per second is equal to a power of 1 watt.

Students should be able to give examples that illustrate the definition of power eg comparing two electric motors that both lift the same weight through the same height but one does it faster than the other.

Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed.

Students should be able to describe with examples where there are energy transfers in a closed system, that there is no net change to the total energy.

Students should be able to describe, with examples, how in all system changes energy is dissipated, so that it is stored in less useful ways. This energy is often described as being ‘wasted’.

Students should be able to explain ways of reducing unwanted energy transfers, for

example through lubrication and the use of thermal insulation.

The higher the thermal conductivity of a material the higher the rate of energy transfer by conduction across the material.

Students should be able to describe how the rate of cooling of a building is affected by the thickness and thermal conductivity of its walls.

The energy efficiency for any energy transfer can be calculated using the equation: efficiency = useful out put energy transfer/total in put energy transfer Efficiency may also be calculated using the equation: efficiency = useful power output/total power input Students should be able to recall and apply both equations.

Students should be able to describe ways to increase the efficiency of an intended energy transfer.

The main energy resources available for use on Earth include: fossil fuels (coal, oil and gas), nuclear fuel, bio-fuel, wind, hydroelectricity, geothermal, the tides, the Sun and water waves.

A renewable energy resource is one that is being (or can be) replenished as it is used.

The uses of energy resources include: transport, electricity generation and heating.

describe the main energy sources available

distinguish between energy resources that are renewable and energy resources that are non-renewable

compare ways that different energy resources are used, the uses to include transport, electricity generation and heating

understand why some energy resources are more reliable than others

describe the environmental impact arising from the use of different energy resources

explain patterns and trends in the use of energy resources.

consider the environmental issues that may arise from the use of different energy resources

show that science has the ability to identify environmental issues arising from the use of energy resources but not always the power to deal with the issues because of political, social, ethical or economic considerations.

Watch: https://www.bbc.co.uk/bitesize/guides/zskp7p3/revision/1

Complete the table

Stores transfers

1.0 A weightlifter picks up a barbell.

1.1 Which type of energy is stored in the barbell when it is held above the weightlifter’s head?

[1 mark]

Tick one box.

Chemical potential

Elastic potential

Gravitational potential

Kinetic

1.2 The weightlifter drops the barbell.

The barbell’s store of which type of energy increases as the barbell falls.

[1 mark]

Tick one box.

Chemical potential

Elastic potential

Gravitational potential

Kinetic

https://www.bbc.co.uk/bitesize/guides/zskp7p3/revision/1

Read and complete the table and questions below

Energy information equation

Kinetic energy

READ: https://www.s-cool.co.uk/gcse/physics/energy-calculations/revise-it/kinetic-energy

Gravitational Potential energy

READ: https://www.s-cool.co.uk/gcse/physics/energy-calculations/revise-it/gravitational-potential-energy

1.3 Use the data in Table 1 to draw a line between each calculation and the energy change it is calculating.

Draw two lines only.

Table 1

mass of barbell 50 kg

gravitational field strength 9.8 m/s2

height the barbell drops 2 m

maximum speed the barbell drops 6.2 m/s

[1 mark]

Calculation Increase/decrease in

Chemical potential energy

50 × 9.8 × 2

Elastic potential energy

Gravitational potential energy

½ × 50 × 6.2 × 6.2

Kinetic energy

Conservation of energy

ACTIVTY http://passmyexams.co.uk/GCSE/physics/conservation-of-energy-and-energy-transfer.html

Complete the statement below

https://www.s-cool.co.uk/gcse/physics/energy-calculations/revise-it/kinetic-energy




https://www.s-cool.co.uk/gcse/physics/energy-calculations/revise-it/gravitational-potential-energy




http://passmyexams.co.uk/GCSE/physics/conservation-of-energy-and-energy-transfer.html

http://passmyexams.co.uk/GCSE/physics/conservation-of-energy-and-energy-transfer.html

Energy is often dissipated

This Sankey diagram shows the energy used in a filament lamp. What percentage of energy is dissipated as heat energy? What does this tell you about the efficiency?

1.4 The weightlifter’s internal store of energy decreased when he lifted the bar.

The bar’s internal store of energy increased by a smaller amount.

Explain why. [2 marks]

_____________________________________________________________________

_____________________________________________________________________

READ: https://www.bbc.co.uk/bitesize/guides/z2wfxfr/revision/2 Use the information to complete these

questions.

Energy source:

Advantage:

Disadvantage:

Energy source:

Advantage:

Disadvantage:

https://www.bbc.co.uk/bitesize/guides/z2wfxfr/revision/2

2.0 Electricity in the UK is produced from a number of energy resources. Figure 1 below shows the proportion of each energy resource used. The labels have been removed from the pie chart.

Figure 1

Energy source:

Advantage:

Disadvantage:

Energy source:

Advantage:

Disadvantage:

Energy source:

Advantage:

Disadvantage:

Energy source:

Advantage:

Disadvantage:

2.1 Complete the table.

[2 marks]

Energy resource Percentage of UK

electricity production Segment label

Coal 23

Natural gas 30

Nuclear power 21

Oil 1

Renewable fuels 25 A

2.2 Over the next 10 years, many of the UK’s nuclear power stations are expected to close. Suggest how this may affect the future balance of sources of energy used for electricity production in the UK.

If we can no longer use Nuclear power then what would the alternative be? Look at the chart on the previous page to suggest and evaluate alternatives.

Write 6 valid point (you can bullet point these)

[6 marks]

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What is this required practical about?

...............................................................................................................................................................

What piece of equipment is used to measure length?

.................................................................................................................................................

Think about how you carried out this practical.

Write a logical and comprehensive method, using numbered bullet points.

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Is your method good?

Read it. If someone else

could get results from it

then yes!

Look at the student’s results below. Work out the force and extension.

Mass added (g) Force (N)

(100g exerts a 1 newton force)

Length (cm) Extension (cm)

0 5

100 10

200 20

300 30

400 40

500 50

600 52

700 52

Sketch a graph of the results you would expect.

Or

Draw a graph of the results on separate paper.

For which ever you do, label: the elastic region, limit of proportionality, estimated point at which the spring

would break.

What is meant by the term directly proportional?

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3.0 A student investigated how the extension of a spring depends on the force applied to the spring.

Figure 2 shows the spring before and after a force has been applied.

Figure 2

3.1 The distance between each large mark on the rule is 10cm. Point A is on a large mark.

State the length of the spring and the extension after the force is applied.

[1 mark]

Length of spring = ______________ cm

Extension = ______________ cm

3.2 The stretched spring stores elastic potential energy. The elastic potential energy stored in a spring can be found by using the equation:

Elastic potential energy = 0.5 × spring constant × (extension)2

A particular spring has a spring constant of 25 N/m.

Calculate the energy stored when the spring is extended by 15 mm. Give your answer in standard form, to 3 significant figures.

[3 marks]

Energy stored = ____________ J

3.3 Another student calculated that the energy stored in her spring was twice the amount of energy for half the extension.

Calculate the spring constant of this spring.

[3 marks]

Spring constant = ____________ N/m

4.0 Figure 3 shows the amount of energy lost at various stages in producing light from an electric light bulb.

Figure 3

4.1 There is no information on one of the energy labels.

What should it say?

[1 mark]

_____________________________________________________________________

4.2 An electricity company wants to reduce wasted energy across a town.

For the same amount of money, they can either:

• Use 20% of the wasted energy from the power station to heat their offices

• Install new power lines which only waste half the energy of the old ones

• Replace all the bulbs in the town with LED bulbs, which are 99% efficient.

Explain which of these things they should do.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

4.3 The lightbulb’s manufacturer says that the lightbulb is 5% efficient. Is this correct?

Use a calculation to justify your answer.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

4.4 Another lightbulb has a power of 12 W. It has an efficiency of 80%. Calculate the amount of time taken in seconds for the bulb to transfer 300 J of energy into light energy.

[3 marks]

Time taken = _______________ s

? 5 J of energy wasted

heating air around

power lines

65 J wasted

heating air in

power station

100 J of

internal

energy in

coal

Power

station Power line

Light bulb

1 J of energy

output as light

Physics: Required Practical 1


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_____________________________________________________________________

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then yes!

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Recall Newton’s Law regarding the conservation of energy.

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What piece of equipment do you use to measure mass?

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What piece of equipment do you use to measure temperature?

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What piece of equipment do you use to measure time?

.................................................................................................................................................

Define: specific heat capacity.

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This practical is about energy transfers.

Recall the equation to calculate the change in thermal energy.

Give the units for each part of the equation.

Define: power

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Define: work done

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There are two equations to calculate power.

Recall both equations below.


READ and WATCH: https://revisionscience.com/gcse-revision/physics/energy-resources-transfer/specific-heat-capacity

5.1 You have been asked to find out the best material for insulating a hot water tank. You have three materials: aluminium foil, cotton wool and expanded polystyrene. Describe an experiment to compare the effectiveness of these materials.

Include in your description the way you would use your results to decide the most effective material.

This means that you will need to use one of the required practicals you have learned. This should give you a clue as to which you will need.

Write 6 valid point (you can bullet point these)

[6 marks]

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https://revisionscience.com/gcse-revision/physics/energy-resources-transfer/specific-heat-capacity

https://revisionscience.com/gcse-revision/physics/energy-resources-transfer/specific-heat-capacity

6.0 A student heated a beaker of water and measured the temperature every minute for 8 minutes. Figure 4 shows the results of their experiment.

Figure 4

Time (minutes)

6.1 The mass of water used was 450 g.

The power of the heater is 300 W.

Calculate the specific heat capacity of the water.

[3 marks]

Specific heat capacity = __________ J/kg°C

6.2 The result of this experiment is higher than the accepted value for water.

Suggest two reasons why this might be.

[2 marks]

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0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8

Temperature

(°C)

Revision Checklist – use this list to identify your areas of strength and weakness to focus your revision

Specification Statement Revised RAG Describe all the changes involved in the way energy is stored when a system changes, for common

situations

Calculate the changes in energy involved when a system is changed Calculate the amount of energy associated with a moving object, a stretched spring and an object raised

above ground level

Determine the specific heat capacity of one or more materials Give examples that illustrate the definition of power e.g. comparing two electric motors that both lift the

same weight through the same height but one does it faster than the other.

Describe with examples where there are energy transfers in a closed system, that there is no net change to the total energy

Describe, with examples, how in all system changes energy is dissipated, so that it is stored in less useful ways

Explain ways of reducing unwanted energy transfers, for example through lubrication and the use of thermal insulation

Describe how the rate of cooling of a building is affected by the thickness and thermal conductivity of its walls

(HT only) Describe ways to increase the efficiency of an intended energy transfer

Describe the main energy sources available

Consider the environmental issues that may arise from the use of different energy resources

Keywords - Use these words to produce a glossary of key terms for this chapter

The topic in pictures – these images are hyperlinked to useful parts of the BBC Bitesize website – use them to access

key revision

Keywords

Gravitational Potential Convection

Gravitational field strength Radiation

Kinetic energy Fossil fuel

Force Generator

Thermal Renewable

Elastic potential Non-renewable

Energy transfer Power

Conduction Work done

Keyword Definition

Gravitational Potential

All images courtesy of the BBC Bitesize website

Energy transfers & efficiency

Work and Power

Non-renewable energy

Renewable energy

http://www.bbc.co.uk/education/guides/zhhcwmn/revision/2

http://www.bbc.co.uk/education/guides/zssk7ty/revision

http://www.bbc.co.uk/education/guides/znn9q6f/revision/1

http://www.bbc.co.uk/education/guides/zpp4jxs/revision/2

Key questions from Physics Topic 1:

1. Write the equation used to calculate the kinetic energy of a moving object.

2. Write the equation used to calculate the amount of elastic potential energy stored in a stretched spring.

3. What is the unit for kinetic energy, gravitational potential energy and elastic potential energy?

4. Write the equation used to calculate the amount of gravitational potential energy gained by an object raised

above ground level.

5. What is the rate at which energy is transferred or work is done?

6. Write two equations to calculate power.

7. What is the unit for Power?

8. What can be transferred usefully, stored or dissipated, but cannot be created or destroyed?

9. Write the equation for calculating the energy efficiency of any energy transfer.

10. What are the three main forms of fossil fuels used as energy resources?

11. State the three principle uses of energy resources.

12. Name seven renewable energy resources available for use on Earth.

13. What is a renewable resource?

Gravitational field strength

Kinetic energy

Force

Thermal

Elastic potential

Energy transfer

Conduction

Convection

Radiation

Fossil fuel

Generator

Renewable

Non-renewable

Power

Work done

Grades 5

Complete: Calculations using equations and remember units!

1. An object moves 5m, the work done is 65J, calculate the force acting on the object.

2. A bus is travelling at 5m/s and has a mass of 500kg. Calculate the kinetic energy.

3. How fast is an object moving if it has 10,000J of kinetic energy and a mass of 5kg?

4. Calculate the GPE a 2kg object that is 10m above the ground (assume gravity is 10N).

5. A spring has a spring constant of 10N/m, the spring has 200J of EPE, calculate the extension of the spring?

6. What is the change in energy if an object with a specific heat capacity of 1200J/kg⁰C and mass of 15kg

increases in temperature by 20⁰C ?

7. What is the total energy transferred by a 200W device if it is on for 20seconds?

8. A light bulb takes in 30J of energy per second. It transfers 3J as useful light energy and 27J as heat energy.

Calculate the efficiency.

acting on the object. 2. A bus is travelling at 5m/s and has a mass of 500kg. Calculate the

kinetic energy. 3. How fast is an object moving if it has 10,000J of kinetic energy

and a mass of 5kg? 4. Calculate the GPE a 2kg object that is 10m above the ground

(assume gravity is 10N). 5. A spring has a spring constant of 10N/m, the spring has 200J of

EPE, calculate the extension of the spring? 6. What is the change in energy if an object with a specific heat

capacity of 1200J/kg⁰C and mass of 15kg increases in temperature by 20⁰C ?

7. What is the total energy transferred by a 200W device if it is on for 20seconds?

8. A light bulb takes in 30J of energy per second. It transfers 3J as useful light energy and 27J as heat energy. Calculate the efficiency.

Answers: 1. 2. 3. 4. 5. 6. 7. 8.

These questions and answers are fundamental to understanding this topic. Use these questions and answers to practice and revise from. Make que cards or simply cover the right hand side of the page and reveal each answer.

Question Answer R/A/G

1 What is the equation linking kinetic energy, mass and velocity?

Ek= 0.5mv2

2 What are the units of energy? joules

3 What are the units of mass? kilograms

4 What are the units of velocity? metres per second

5 What is the equation linking gravitational field strength, gravitational potential energy and height?

Ep=mgh

6 What are the units of gravitational field strength?

newtons per kilogram

7 What is the equation linking energy transferred, power and time?

P=E/t

8 What are the units of power? Watts

9 What is the definition of power? Power is the rate of transfer of energy or the rate of doing work

10 What is the equation linking power, time and work done?

P=W/t

11 What are the units of work done? Joules

12 What is the equation for calculating efficiency from energy?

Efficiency = useful energy output/total energy input

13 What is the equation for calculating efficiency from power?

Efficiency = useful power output/useful power input

14 What is the type of energy transferred when a force moves through a distance?

Mechanical transfer

15 Mechanical transfer is…? The energy transfer when a force moves through a distance

16 Electrical transfer is…? energy transferred when a charge moves?

17 What is the energy transferred when a charge moves?

electrical transfer

18 What is the energy transferred by electromagnetic radiation?

Radiation transfer

19 Radiation transfer is…? The energy transferred by electromagnetic radiation.

20 Heat transfer is…? Energy transferred when an object is heated.

21 When an object is heated the energy transfer is a…?

heat transfer

22 List the 4 energy transfer pathways. Mechanical, electrical, radiation and heat.

23 List 4 energy stores. Four from: chemical, kinetic, gravitational potential, elastic potential, internal, nuclear, magnetic, electrostatic.

24 Energy stored in objects which move. Kinetic

25 What is a kinetic energy store Energy stored in objects which move

26 Chemical energy is stored as…? chemicals waiting to react

27 A battery is a store of __________ energy. Chemical

28 Food is a store of __________ energy. Chemical

29 A moving object is a store of ____________ energy

Kinetic

30 What is a gravitational potential store? energy stored in objects raised up against the force of gravity.

31 A rock at the top of a hill is a store of gravitational potential

___________ energy.

32 What is an elastic potential store? Energy stored in an object which has been stretched or compressed.

33 A compressed spring is a store of ___________ energy

elastic potential

34 An inflated balloon is a store of __________ energy

elastic potential

35 The internal energy store is… energy stored in the movement of particles.

36 The internal energy store of an object can be changed by…?

heating or cooling

37 Energy stored in the nuclei of atoms is in the __________ store.

Nuclear

38 What is a nuclear energy store? Energy stored in the nuclei of atoms that can fuse or split.

39 What is the magnetic energy store? Energy stored in magnets that are attracting or repelling

40 What is the electrostatic energy store? Energy stored n electric charges that are attracting or repelling

41 Name two non-renewable energy resources Fossil fuels, nuclear fuel

42 What are some advantages of fossil fuels as an energy resource?

reliable, cheap

43 What is a reliable energy source one which can produce energy all the time.

44 What are some disadvantages of fossil fuels? carbon dioxide (greenhouse gas) produced leading to global warming. Can produce sulphur dioxide causing acid rain.

45 What are some advantages of nuclear fuel? No carbon dioxide produced, reliable.

46 What are some disadvantages of nuclear fuel?

nuclear waste remains radioactive for thousands of years. Expensive to build and decommission

47 List 4 renewable energy resources. Any 4 from: biofuel, wind, hydroelectricity, geothermal, tidal, wave, solar.

48 What are some advantages of biofuels? carbon neutral, reliable

49 What are some disadvantages of biofuels? production of fuel can damage ecosystems and reduce variety of crops grown

50 What are some advantages of wind power? No carbon dioxide produced

51 What are some disadvantages of wind power?

unreliable, expensive to construct

52 What are some advantages of hydroelectricity?

No carbon dioxide produced

53 What are some disadvantages of hydroelectricity?

blocks rivers preventing fish migration, unreliable (may not produce electricity during droughts)

54 What are some advantages of geothermal energy?

doesn't damage ecosystems, reliable.

55 What are some disadvantages of geothermal energy?

fluids drawn from ground may contain greenhouse gases such as CO2 and methane. These contribute to global warming

56 What are some advantages of tidal energy? No carbon dioxide produced.

57 What are some disadvantages of tidal energy?

unreliable - tides vary, may damage tidal ecosystem

58 What are some advantages of wave power? No carbon dioxide produced

59 What are some disadvantages of wave power?

unreliable - may not produce electricity when calm seas

60 What are some advantages of solar power? No carbon dioxide produced

61 What are some disadvantages of solar power?

unreliable - no electricity produced at night and limited on cloudy days. Expensive to construct.

62 What term is used to describe energy dissipation

becoming spread out or transferred to a "wasted" store?

63 What term is used to describe a method for reducing unwanted energy transfers by reducing friction?

lubrication

64 What is a thermal insulator? A non-conductive material which reduces thermal energy transfers.

65 What is the name for a method of reducing energy transfers by the use of non-conductive materials?

insulation

66 What is the law of conservation of energy? Energy cannot be created and destroyed but only transferred from one store to another.

67 Define specific heat capacity The energy needed to raise the temperature 1 kg of a material by 1ᵒC

Physics 2: Simple Circuits

Simple circuits check

foundation higher triple

circuit diagram symbols

Circuit diagrams use standard symbols for a switch, cell, battery, diode, resistor, variable resistor, LED, lamp, fuse, voltmeter, ammeter, thermistor, LDR

Electrical charge and

current

For electrical charge to flow through a closed circuit the circuit must include a source of potential difference.

Electric current is a flow of electrical charge. The size of the electric current is the rate of flow of electrical charge.

Students should be able to recall and apply charge flow = current × time equation.

A current has the same value at any point in a single closed loop.

Current, resistance

and potential difference

The current (I) through a component depends on both the resistance (R) of the component and the potential difference (V) across the component. The greater the resistance of the component the smaller the current for a given potential difference (pd) across the component.

Students should be able to recall and apply potential difference = current × resistance equation.

Required practical activity 3

Use circuit diagrams to set up and check appropriate circuits to investigate the factors affecting the resistance of electrical circuits. This should include: • the length of a wire at constant temperature • combinations of resistors in series and parallel.

Resistors

Students should be able to explain that, for some resistors, the value of R remains constant but that in others it can change as the current changes.

The current through an ohmic conductor (at a constant temperature) is directly proportional to the potential difference across the resistor. This means that the resistance remains constant as the current changes.

The resistance of components such as lamps, diodes, thermistors and LDRs is not constant; it changes with the current through the component.

The resistance of a filament lamp increases as the temperature of the filament increases.

The current through a diode flows in one direction only. The diode has a very high resistance in the reverse direction.

The resistance of a thermistor decreases as the temperature increases.

The applications of thermistors in circuits eg a thermostat is required.

The resistance of an LDR decreases as light intensity increases.

The application of LDRs in circuits eg switching lights on when it gets dark is required.

explain the design and use of a circuit to measure the resistance of a component by measuring the current through, and potential difference across, the component

draw an appropriate circuit diagram using correct circuit symbols.

Students should be able to use graphs to explore whether circuit elements are linear or non-linear and relate the curves produced to their function and properties.


use circuit diagrams to construct appropriate circuits to investigate the I–V characteristics of a variety of circuit elements, including a filament lamp, a diode and a resistor at constant temperature.

Series and parallel circuits

There are two ways of joining electrical components, in series and in parallel. Some circuits include both series and parallel parts.

For components connected in series: • there is the same current through each component • the total potential difference of the power supply is shared between the components • the total resistance of two components is the sum of the resistance of each component.

For components connected in parallel: • the potential difference across each component is the same • the total current through the whole circuit is the sum of the currents through the separate components • the total resistance of two resistors is less than the resistance of the smallest individual resistor.

use circuit diagrams to construct and check series and parallel circuits that include a variety of common circuit components

describe the difference between series and parallel circuits

explain qualitatively why adding resistors in series increases the total resistance whilst adding resistors in parallel decreases the total resistance

explain the design and use of dc series circuits for measurement and testing purposes

calculate the currents, potential differences and resistances in dc series circuits

solve problems for circuits which include resistors in series using the concept of equivalent resistance.

Direct and alternating potential difference

Mains electricity is an ac supply. In the United Kingdom the domestic electricity supply has a frequency of 50 Hz and is about 230 V.

Students should be able to explain the difference between direct and alternating potential difference.

Most electrical appliances are connected to the mains using three core cable. The insulation covering each wire is colour coded for easy identification: live wire – brown, neutral wire – blue, earth wire – green and yellow stripes.

The live wire carries the alternating potential difference from the supply. The neutral wire completes the circuit. The earth wire is a safety wire to stop the appliance becoming live.

The potential difference between the live wire and earth (0 V) is about 230 V. The neutral wire is at, or close to, earth potential (0 V). The earth wire is at 0 V, it only carries a current if there is a fault.

Explain that a live wire may be dangerous even when a switch in the mains circuit is open

Explain the dangers of providing any connection between the live wire and earth.

Power

Students should be able to explain how the power transfer in any circuit device is related to the potential difference across it and the current through it, and to the energy changes over time

Students should be able to recall and apply both equations. power = potential difference × current power = current2 × resistance

Energy transfers in

everyday appliances

Everyday electrical appliances are designed to bring about energy transfers.

The amount of energy an appliance transfers depends on how long the appliance is switched on for and the power of the appliance.

Students should be able to describe how different domestic appliances transfer energy from batteries or ac mains to the kinetic energy of electric motors or the energy of heating devices.

Work is done when charge flows in a circuit.

Students should be able to recall and apply both equations. energy transferred = power × time energy transferred = charge flow × potential difference

explain how the power of a circuit device is related to the potential difference across it and the current through it

explain how the power of a circuit device is related to the energy transferred over a given time.

Students should be able to describe, with examples, the relationship between the power ratings for electrical appliances and the changes in stored energy when they are in use.

The National

Grid

The National Grid is a system of cables and transformers linking power stations to consumers.

Electrical power is transferred from power stations to consumers using the National Grid.

Step-up transformers are used to increase the potential difference from the power station to the transmission cables then step-down transformers are used to decrease, to a much lower value, the potential difference for domestic use.

Students should be able to explain why the National Grid system is an efficient way to transfer energy.

6-2 Electricity

READ: https://www.bbc.co.uk/bitesize/guides/zw8n2nb/revision/1

1.0 Most domestic appliances are connected to the mains electricity.

1.1 What is the frequency of mains electricity?

Tick one box

[1 mark]

1.05 A

50 Hz

230 V

1.2 What is the potential difference of mains electricity?

Tick one box

[1 mark]

1.05 A

50 Hz

230 V

READ and ACTIVITY: http://passmyexams.co.uk/GCSE/physics/structure-of-three-3-pin-plug.html

Label the diagram and explain each part

1.3 Most domestic appliances are connected to the mains electricity with a plug.

Explain why a plug needs a live and a neutral wire.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

https://www.bbc.co.uk/bitesize/guides/zw8n2nb/revision/1

http://passmyexams.co.uk/GCSE/physics/structure-of-three-3-pin-plug.html

A

V

A

V

mA

V

1.4 The law specifies the colour that mains wires should be for all domestic electrical circuits.

It is important that the live wire is easy to identify to reduce the risk of an electric shock.

Explain how an electric shock can be caused by a person touching the live wire.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

1.5 An iron is supplied with a current of 3 A from the mains. The resistance of the iron is 100 Ω.

Calculate the power of the iron.

[2 marks]

Power = ______________ W



...............................................................................................................................................................

Label the equipment in each diagram.

Think about how you carried out the first circuit practical.





then yes!

Recall the equation that links current and voltage.

.................................................................................................................................................

What does an ammeter measure, and what are the units? (there are two words that can be used

interchangeably here, give them both)

.................................................................................................................................................

What does a voltmeter measure, and what are the units?

.................................................................................................................................................

What does a resistor measure, and what are the units?

.................................................................................................................................................

Which equation is used to represent a linear relationship?

.................................................................................................................................................

When recording results from the experiments above, why should the student ensure all of results are

recorded to the same number of significant figures?

.................................................................................................................................................

.................................................................................................................................................

What is the difference between significant figures and decimal places?

.................................................................................................................................................

.................................................................................................................................................

Sketch the results you would expect to see for each of the following:

Resistor/wire Filament Lamp Diode

Current

Voltage

Current

Voltage

Current

Voltage

2.0 A student wants to investigate how the current through a filament lamp affects its resistance.

2.1 Use the circuit symbols in Figure 1 to draw a circuit diagram that he could use.

[2 marks]

Figure 1

12 V battery variable resistor

filament lamp

voltmeter ammeter

2.2 Describe how the student could use her circuit to investigate how the current through a filament lamp affects its resistance.

[4 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

REVISE: this equation V = I R

What do each parts of the sentence stand for? Give the units.

V =

I =

R =

TRY: these questions https://www.bbc.co.uk/bitesize/guides/z8b2pv4/test

WATCH:https://www.bing.com/videos/search?q=revise+series+circuits+resistance&view=detail&mid=8C780AC62CE

75BC00FCA8C780AC62CE75BC00FCA&FORM=VIRE (skip to 2mins if you want to just see the resistance)

https://www.bbc.co.uk/bitesize/guides/z8b2pv4/test

https://www.bing.com/videos/search?q=revise+series+circuits+resistance&view=detail&mid=8C780AC62CE75BC00FCA8C780AC62CE75BC00FCA&FORM=VIRE

https://www.bing.com/videos/search?q=revise+series+circuits+resistance&view=detail&mid=8C780AC62CE75BC00FCA8C780AC62CE75BC00FCA&FORM=VIRE

TRY: https://phet.colorado.edu/en/simulation/ohms-law

3.0 A student sets up the electrical circuit shown in Figure 2 below.

Figure 2

3.1 The ammeter displays a reading of 0.025 A.

Calculate the potential difference across the 75 Ω resistor.

Give your answer to 2 significant figures.

[2 marks]

Potential difference = _______________ V

3.2 Calculate the resistance of the resistor labelled R.

[3 marks]

Resistance = __________________ Ω

3.3 State what happens to the total resistance of the circuit and the current through the circuit when switch S is closed.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

6V

75Ω

150Ω

https://phet.colorado.edu/en/simulation/ohms-law



...............................................................................................................................................................

Draw a circuit diagram to show how this piece of equipment (above) is put into a circuit.

Also include: one battery, one voltmeter, one ammeter, one bulb



Draw a circuit diagram which includes: one battery, one voltmeter, one ammeter and two bulbs in series.




then yes!

Draw a circuit diagram which includes: one battery, one voltmeter, one ammeter and two bulbs in parallel.

Recall the two factors which affect the resistance of an electrical circuit. For each one, outline how it affects

the resistance.

1. ...............................................................................................................................................

...............................................................................................................................................

2. ...............................................................................................................................................

...............................................................................................................................................

What does an ammeter measure, and what are the units? (there are two words that can be used

interchangeably here, give them both)

.................................................................................................................................................

What does a voltmeter measure, and what are the units?

.................................................................................................................................................

What does a resistor measure, and what are the units?

.................................................................................................................................................


.................................................................................................................................................

Recall the equation that links the size of the electric current and the flow of electrical charge below.


Recall the equation that links potential difference, current and resistance below.


Which equation is used to represent a linear relationship?

.................................................................................................................................................

Watch this video: https://www.youtube.com/watch?v=WzSh6ykqn9I

Try these questions: https://www.bbc.co.uk/bitesize/guides/zx7vw6f/revision/5

4.0 A student investigated how current varies with potential difference for two different lamps of the same type.

Her results are shown in the Figure 3 below.

Figure 3

https://www.youtube.com/watch?v=WzSh6ykqn9I

https://www.bbc.co.uk/bitesize/guides/zx7vw6f/revision/5

4.1 Draw the circuit diagram for the circuit that the student could have used to obtain the results shown in the figure above.

[3 marks]

4.2 The student made the following conclusion,

‘Lamp A is twice a bright as lamp B’.

Use data from Figure 3 to explain why the student’s conclusion is correct.

[3 marks]

_____________________________________________________________________

____________________________________________________________________

_____________________________________________________________________

4.3 The resistance of each lamp increases as the current increases.

Calculate the difference between the lowest and highest values of resistance for lamp A from Figure 3.

[3 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________


Specification Statement Revised RAG Use circuit diagrams to set up and check appropriate circuits to investigate the factors affecting the

resistance of electrical circuits

Explain that, for some resistors, the value of R remains constant but that in others it can change as the current changes

Explain the design and use of a circuit to measure the resistance of a component by measuring the current through, and potential difference across, the component

Draw an appropriate circuit diagram using correct circuit symbols Use graphs to explore whether circuit elements are linear or non-linear and relate the curves produced to

their function and properties

Use circuit diagrams to construct appropriate circuits to investigate the I–V characteristics of a variety of circuit elements, including a filament lamp, a diode and a resistor at constant temperature

Describe the difference between series and parallel circuits

Calculate the currents, potential differences and resistances in dc series circuits

Explain the difference between direct and alternating potential difference

Explain that a live wire may be dangerous even when a switch in the mains circuit is open Explain how the power transfer in any circuit device is related to the potential difference across it and the

current through it, and to the energy changes over time

Describe how different domestic appliances transfer energy from batteries or ac mains to the kinetic energy of electric motors or the energy of heating devices

Describe, with examples, the relationship between the power ratings for domestic electrical appliances and the changes in stored energy when they are in use

Explain why the National Grid system is an efficient way to transfer energy



key revision

Keywords

Live Parallel circuit

Neutral Voltmeter

Earth Ammeter

Fuse Transformer

Current Diode

Potential difference LDR

Resistance Thermistor

Series circuit Filament lamp

Keyword Definition

Live


Electrical safety

Circuits, AC & DC

Current, voltage & resistance

Filament lamps, resistors and diodes

http://www.bbc.co.uk/education/guides/zwwnb9q/revision/2

http://www.bbc.co.uk/education/guides/zddp34j/revision

http://www.bbc.co.uk/education/guides/z88hvcw/revision

http://www.bbc.co.uk/education/guides/zqqfr82/revision/1


1. State what the following symbols show:

2. Write the equation used to calculate current, potential difference or resistance.

3. What is the unit for resistance?

4. Which of the following graphs shows resistance in a filament lamp?

5. Which of the following graphs shows resistance in a diode?

Neutral

Earth

Fuse

Current

Potential difference

Resistance

Series circuit

Parallel circuit

Voltmeter

Ammeter

Transformer

Diode

LDR

Thermistor

6. What happens to the resistance of a thermistor as the temperature increases?

7. What happens to the resistance of an LDR as the light intensity increases?

8. Describe the current in a series circuit.

9. Describe the potential difference in a series circuit.

10. Describe resistance in a parallel circuit.

11. Describe domestic mains electricity supply in the UK.

12. What colour is the insulation on wires in a plug?

Live wire –

Neutral wire –

Earth wire –

13. Write two equations for calculating power transfer in an electric circuit.

14. What does the amount of energy an appliance transfers depend on?

15. What are the two equations for calculating the amount of energy transferred by electrical work?

16. How is electrical power transferred from power stations to consumers?

Grade 5

Series & Parallel Circuits

Diagram 1 Diagram 2

1. What components do the letters A, B and C represent?

A................................. B..................................... C...................................

2. What is the name given to the way the bulbs are arranged in Diagram 1?

....................................................................................................................................................

3. What is the name given to the way the bulbs are arranged in Diagram 2?

....................................................................................................................................................

4. In a series circuit, like in Diagram 1, how is the brightness of the first bulb affected when the second bulb is connected? Explain why this happens?

....................................................................................................................................................

....................................................................................................................................................

5. In a parallel circuit, like in Diagram 2, how is the brightness of the first bulb affected when the second bulb is connected? Explain why this happens?

....................................................................................................................................................

....................................................................................................................................................

A

B

C

6. Give one example of where we might find a series circuit in everyday life.

....................................................................................................................................................

7. Give one example of where we might find a parallel circuit in everyday life.

....................................................................................................................................................

8. Explain one advantage of using a parallel circuit rather than a series circuit.

....................................................................................................................................................

9. Dan and Tom build a circuit like the one shown below.

(a) Name the component labelled X ........................................................

(b) What are Dan and Tom using the component labelled X to measure? ................................

(c) Dan says, “Ammeter 1 will show a lower reading than Ammeter 2 because the bulbs in the circuit use up the current.” Tom says, “Ammeter 1 will show the same reading as Ammeter 2 because current is not used up.”

Who is right? ..................................................

(d) If Ammeter 1 has a reading of 1.5A, what reading will Ammeter 2 show? ....................A

10. (a) The circuit above contains 2 cells. Describe what would happen to the bulbs if Dan and Tom added another cell.

....................................................................................................................................................

(b) Describe how the reading on the reading on the ammeters would change if another cell was added to the circuit.

....................................................................................................................................................

X

Current

What is the current when...

1. 100 C of charge flows through a cell in 20 s?

2. 20,000 C of charge flows through a lamp in 1800 s?

3. 500,000 C of charge flows in 1 hour?

How much charge flows through a cell when...

4. A current of 1 A flows for 1 s?

5. A current of 3 A flows for 45 s?

6. A current of 5 A flows for 10 minutes?

How long does it take for...

7. A current of 3 A to transfer 90 C of charge?

8. A current of 1 A to transfer 90 C of charge?

9. A current of 5 A to transfer 1,000,000 C of charge?

Potential Difference Complete the following diagrams by filling in the missing values:

1. 2. 3.

4. 5. 6.

I = Q/t

2.5V

V

2.5V

2.5V

V

5V

V

3V 3V

V

3V

V

Current & Potential Difference Complete the following diagram by filling in the missing values:

Current, Potential Difference, & Resistance

What is the resistance of...

1. a fixed resistor with a potential difference of 5 V and a current of 0.1 A?

2. a thermistor with a potential difference of 10 V and a current of 0.5 A?

3. a LDR with a potential difference of 3 V and a current of 0.01 A?

How much current will be flowing when...

4. a potential difference of 2 V is applied across an LED with a resistance of 20 Ω?

5. a potential difference of 12 V is applied across a 500 Ω resistor?

6. a potential difference of 1.5 V is applied across an thermistor with a resistance of 30 Ω?

What potential difference is needed to make...

7. a current of 1 A to flow through a 1 Ω resistor?



Current, Potential Difference, & Power

What is the power rating of a bulb where...

1. The potential difference is 240 V and the current is 0.25 A?



How much current flows through the following appliances when connected to a 240 V mains power

supply?

4. A 2000 W kettle?

5. A 1.2 kW microwave?

6. A 400 W computer?

How much energy is transferred in each of the above when connected for...

7. 10 seconds?

8. 2 minutes?

9. 1 hour?

V = I x R

3V

V

0.2A

V

A1

V

V1

V

V2

V

V3

V

A2

V

P = I x V

E = P x t

Current

1. 100/20 = 5 A 2. 1800 s? 20,000/1800 = 11 A 3. 500,000/(1 x 60 x 60) = 138.9 ≈ 140 A 4. 1 x 1 = 1 C 5. 3 x 45 = 135 C 6. ? 5 x (10 x 60) = 3000 C 7. 90/3 = 30 s 8. 90/1 = 90 s 9. 1,000,000/5 = 200,000 s

Potential difference

1. 2.5 2. 1.25V, 1.25V 3. 2.5 4. 3V, 3V 5. 1.5V, 1.5V, 1.5V, 1.5V. 6. 3V, 1.5V, 1.5V,

Current and Potential Difference

A1 – 0.1 A A2 – 0.3 A V1 – 3 V V2 – 1.5 V V3 – 1.5 V

Current, Potential Difference, & Resistance

1. 5/0.1 = 50 Ω 2. 10/0.5 = 20 Ω 3. 3/0.01 = 300 Ω 4. 2/20 = 0.1 A 5. 12/500 = 0.024 A 6. 1.5/30 = 0.05 A 7. 1 x 1 = 1 V 8. 3 x 30 = 90 V 9. 2 x 40 = 80 V

Current, Potential Difference, & Power

1. 25 x 240 = 60 W 2. 0.5 x 120 = 60 W 3. 0.167 x 240 = 40 W

4. 2000/240 = 8.3 A 5. 2000/240 = 5 A 6. 400/240 = 1.7 A 7. Kettle: 2000 x 10 = 20,000 J Microwave: 1200

x 10 = 12,000 J Computer: 400 x 10 = 4,000 J 8. Kettle: 2000 x 120 = 240,000 J Microwave:

1200 x 120 = 144,000 J Computer: 400 x 120 = 48,000 J

9. Kettle: 2000 x 3600 = 7,200,000 J Microwave: 1200 x 4,320,000 = 12,000 J Computer: 400 x 3600 = 1,440,000 J

Grade 5

Series Circuits

In a series circuit, the components are connected in a _____________, between the ______________ and _________________ ends of the power supply, except for __________________ which are connected in parallel to the components. A break in any point in the circuit means that current cannot flow in a complete loop and the circuit will not work.

The current (A) is the ____________ throughout a series circuit

V = IR

The potential difference (voltage) in a series circuit is ________________ between the components. The total potential difference (voltage) is the sum of the potential difference (voltage) of the components.

Vtotal

= V1 + V

2 + V

3 + etc.

Itotal

= I1 = I

2 = I

3 = etc.

The resistance in a series circuit is the ______________ of all the resistances added together.

Rtotal

= R1 + R

2 + R

3 + etc.

By adding a resistor into the circuit, the two resistors must share the total p.d.. This means that the p.d. is lower. This makes the current lower as well. The bigger the resistor, the _____________ of the total p.d. it takes

Summary of series circuits

1. The pd of the cells adds up to the ____________ pd.

2. The source pd is _____________ across the components.

3. The current is the _____________ throughout the components

4. The total resistance of the circuit is the _________ of all the resistances of the separate components.

sum same source split

2V 2V 2V

2V + 2V + 2V = 6V

Reminder! The total potential difference across a circuit is the sum of the pds of the batteries. We refer to the sum total of the potential differences as the ‘source’ pd

Potential difference is the energy transferred to or from a coulomb (Q or C)

total

1

2

etc.

Parallel Circuits

In a parallel circuit the current ____________ into different branches and then recombines before it goes back into the supply. The total current flowing around the circuit is ____________ to the total of all the currents in all the branches. Remember that current is the flow of electrons. Each electron can only take one path.

V = p.d. (potential difference or voltage) I = current (amps or A) R = resistance (ohms or Ω)

V = IR

Components connected in parallel each have their own _____________ connected to the positive and negative terminals (except _____________, which are always connected in series). A break in the circuit will only affect that loop and not the others. _______________ will still flow to the loops that are connected.

In a parallel circuit the potential difference is the __________ for each component. Each coulomb of charge can only take _________ path. It ‘gives up’ its energy to the component in that pathway. This means that the ______________ _______________ is the same for each component in the circuit.

REMEMBER!! Potential difference is the energy transferred to or from a coulomb of charge (Q or C)

Vtotal

= V1 = V

2 = V

3 = etc.

In a parallel circuit, the total resistance is ________ than the resistance of the _____________ resistor (the component with least resistance). (Think back to the lunch queue analogy.) If __________ loops are added, there are more pathways for the current to take, which means that the resistance __________. Using V = IR, we know that an __________ in current means a ______________ in resistance.

1

𝑅𝑡𝑜𝑡𝑎𝑙=

1

𝑅1+

1

𝑅2+

1

𝑅3

+ 𝑒𝑡𝑐. You DO NOT need to remember this equation for the exam. Only that the total resistance is less than that of the smallest resistor.



70 Draw the circuit symbol for a switch

71 Draw the circuit symbol for a closed switch

72 Draw the circuit symbol for a cell

73 Draw the circuit symbol for a battery

74 Draw the circuit symbol for a diode

75 Draw the circuit symbol for a resistor

76 Draw the circuit symbol for a variable resistor

77 Draw the circuit symbol for an LED

78 Draw the circuit symbol for a lamp

79 Draw the circuit symbol for a fuse

80 Draw the circuit symbol for a voltmeter

81 Draw the circuit symbol for an ammeter

82 Draw the circuit symbol for a thermistor

83 Draw the circuit symbol for an LDR

84 State the rule for current in a series circuit the current is the same at every point in the circuit and in every component

85 State the rule for potential difference in a series circuit

the total potential difference of the power supply is shared between components

86 State the rule for resistance in a series circuit

the more resistors, the greater the resistance. RT=R1+R2

87 State the rule for current in a parallel circuit

the total current through the whole circuit is the sum of the currents through the separate components

88 State the rule for potential difference in a parallel circuit

the potential difference across each branch in the circuit is the same

89 State the rule for resistance in a parallel circuit

adding more resistors in parallel decreases resistance

90 What colour is the live wire in a three core cable?

brown

91 What colour is the neutral wire in a three core cable?

blue

92 What colour is the earth wire in a three core cable?

green and yellow

93 The brown wire in a plug is the _______ live

94 The blue wire in a plug is the ________ neutral

95 The green and yellow wire in a plug is the ________

earth

96 The potential difference between the live wire and others in the plug is _____ V

230V

97 Current flows into an appliance through the _______ wire

live

98 Current flows out of an appliance through the ______ wire

neutral

99 The _________ wire is a safety feature of appliances

earth

100 Potential difference between the neutral wires and others in the plug should be ____ V

0V

101 Electric Current is….? the flow of electric charge

102 Potential difference between two points in a circuit is….?

the work done when a couloumb of charge passes between the points.

103 In a circuit the potential difference causes …..?

charge to flow

104 Resistance is…? caused by anything which opposes the flow of electric charge

105 Particles which can be 'charges' in electric circuits are…

electrons or ions

106 What is a series circuit? A circuit with only one route for charge to flow

107 What is a parallel circuit? A circuit with more than one route for charge to flow

108 State the equation which links charge flow, current and time

Q=It

109 State the equation which links current, potential difference and resistance

V=IR

110 State the equation which links current, potential difference and power

P=IV

111 State the equation which links current, power and resistance

P=I2R

112 State the equation which links energy transferred, power and time

E=Pt

113 State the equation which links charge flow, energy transferred and potential difference

E=QV

114 What is the unit of charge flow? Coulomb ( C )

115 What is the unit of current? Amps (A)

116 What is the unit for potential difference? Volts (V)

117 What is the unit for resistance? Ohms (Ω)

118 What is the unit for power? Watts (W)

119 Draw the I-V characteristic for a fixed resistor

120 Draw the I-V characteristic for a filament lamp see

121 Draw the I-V characteristic for a diode

122 Describe the I-V characteristic for a fixed resistor

Current and potential difference are directly proportional, resistance is constant

123 Describe the I-V characteristic of a filament lamp

Resistance is not constant, it increases as p.d. increases

124 Explain why resistance increases with increased p.d. in a filament lamp

temperature increases causing ions to vibrate and increasing collisions with electrons flowing through the filament

125 Describe the I-V characteristic of a diode The current only flows through the diode in one direction, there is a very high resistance in the reverse direction.

126 Current which regularly changes direction is called…

alternating current

127 An example of alternating current is…? mains electricity

128 Current which flows in one direction is…? direct current

129 An example of direct current is… batteries

130 What is the potential difference of mains electricity in the UK?

230V

131 What is the frequency of the alternating current in UK mains electricity?

50Hz

132 The national grid consists of…? Cables and transformers

133 Are power stations par of the national grid?

no

134 What does a step up transformer do? Increases p.d.

135 What does a step down transformer do? reduces p.d. to 230 V

136 Why are transformers used? reduce current so that less heat is lost in cables, increases efficiency

Science Faculty Physics 3: Particles Checklist

Particles

Density of materials

Students should be able to recall and apply the density equation to changes where mass is conserved. density = mass/volume

Students should be able to recognise/draw simple diagrams to model the difference between solids, liquids and gases.

Students should be able to explain the differences in density between the different states of matter in terms of the arrangement of atoms or molecules.

Required practical

activity 5:

Use appropriate apparatus to make and record the measurements needed to determine the densities of regular and irregular solid objects and liquids. Volume should be determined from the dimensions of regularly shaped objects, and by a displacement technique for irregularly shaped objects. Dimensions to be measured using appropriate apparatus such as a ruler, micrometer or Vernier callipers.

Changes of state

Students should be able to describe how, when substances change state (melt, freeze, boil, evaporate, condense or sublimate), mass is conserved.

Changes of state are physical changes which differ from chemical changes because the material recovers its original properties if the change is reversed.

Internal energy

Energy is stored inside a system by the particles (atoms and molecules) that make up the system. This is called internal energy.

Internal energy is the total kinetic energy and potential energy of all the particles (atoms and molecules) that make up a system.

Heating changes the energy stored within the system by increasing the energy of the particles that make up the system. This either raises the temperature of the system or produces a change of state.

Temperature changes in a system

If the temperature of the system increases, the increase in temperature depends on the mass of the substance heated, the type of material and the energy input to the system.

The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

Students should be able to apply Δ E m c Δ θ equation, which is given on the Physics equation sheet, to calculate the energy change involved when the temperature of a material changes.

Changes of heat and specific

latent heat

If a change of state happens: The energy needed for a substance to change state is called latent heat. When a change of state occurs, the energy supplied changes the energy stored (internal energy) but not the temperature.

The specific latent heat of a substance is the amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Specific latent heat of fusion – change of state from solid to liquid/Specific latent heat of vaporisation – change of state from liquid to vapour

Students should be able to apply E = m L equation, which is given on the Physics equation sheet, to calculate the energy change involved in a change of state.

Students should be able to interpret heating and cooling graphs that include changes of state.

Students should be able to distinguish between specific heat capacity and specific latent heat.

Particle motion in

gases

The molecules of a gas are in constant random motion. The temperature of the gas is related to the average kinetic energy of the molecules.

Changing the temperature of a gas, held at constant volume, changes the pressure exerted by the gas.

explain how the motion of the molecules in a gas is related to both its temperature and its pressure

explain qualitatively the relation between the temperature of a gas and its pressure at constant volume.

Matter: Kinetic Molecular Model, and Thermal Properties In these notes: bullet points are from the Cambridge IGCSE syllabus. Text in italics is supplementary (extended).

1. Solids, Liquids and Gases: Properties and Particles

State the distinguishing properties of solids, liquids and gases.

Describe qualitatively the molecular structure of solids, liquids and gases.

Relate the properties of solids, liquids and gases to the forces and distances between molecules and to the motion of the molecules.

State Distinguishing Property Explanation in terms of particles

Solid (Atoms/molecules held very close together by strong attractions. They stay in their positions, but vibrate – move repeatedly backwards and forwards.)

The particles are strongly attracted and can’t change their positions.

The particles are very close together (and if you try to push them closer, they repel each other).

Liquid (Atoms/molecules are very close together but the attractions are weaker than in a solid. So they can move around, changing positions. Neighbouring particles may be temporarily attracted, but then break apart again.)

The particles are not strongly attracted, so they can move past each other.

Gravity pulls the liquid down, and the particles can’t escape from each other because they are attracted. But the attractions are not strong, so the particles move around and the liquid flows to fill the bottom of the container.

The particles are very close together (and if you try to push them closer, they repel each other).

Gas (Atoms/molecules are far apart, and there is no attraction between them. They move in random directions, at high speed.)

The particles are not attracted, so they do not stay together. (This is beyond IGCSE, but in case you’re wondering: gas particles can ‘defy’ gravity because they have a lot of energy for their size. Like a fast-moving rocket or a firework, they are energetic enough to overcome gravity.)

The particles are far apart, so they can be pushed closer together.

Not many particles per unit volume, so has a low mass per unit volume.

Warning! Students often think the particles are significantly farther apart in a liquid than in a solid. This is not true. If you draw the particles in a liquid, you should draw them touching.

The world ‘particles’ is used a lot below. It can mean either atoms, or molecules (two or more atoms bonded together). For example, a particle of iron is simply a single iron atom; whereas a particle of water is a molecule of H2O (two hydrogen atoms and one oxygen atom, bonded together), and a particle of sucrose is the molecule C12H22O11.

2. Heat and Temperature

Interpret the temperature of a gas in terms of the motion of its molecules. Firstly, heat and temperature are not the same thing (although they are related). Heat: a type of _____________. Heat can be transferred from one object or place to another, and we measure amounts of heat in ____________. When some heat enters an object, its temperature usually _______ (but not always – see later). Temperature: the temperature of an object is related to the average kinetic energy of its particles. The faster its particles are moving (either vibrating or moving around), the _________ its temperature. (Beyond IGCSE: the temperature of an object is directly proportional to the average kinetic energy of its particles.) Usually if you give an object some more heat, that extra energy is shared between the object’s particles. The average kinetic energy (and the speed) of the particles increases. This means it has a higher ________________ than before.

3. Thermal Expansion

Describe qualitatively the thermal expansion of solids, liquids and gases.

Identify and explain some of the everyday applications and consequences of thermal expansion.

Explain in terms of motion and arrangement of molecules the relative order of magnitude of the expansion of solids, liquids and gases.

Thermal expansion can be explained by the kinetic molecular model of matter. If the temperature of a substance rises, that means its particles are moving faster. This causes changes we can measure and sometimes actually see:

Solid Liquid Gas

The particles vibrate faster and farther. They push each other farther apart, so the solid expands a little.

The particles move around faster. They hit each other with more force, pushing each other farther apart. So the liquid expands a little.

The particles move around faster. They hit the insides of their container harder and more often. If the container is able to be pushed outwards by their increased force (e.g. a balloon, a syringe), then the gas will expand. Gases expand much more than solids and liquids.

Particles in a solid ___________ ___________________________ ___________________________; this stops them moving much farther apart, so the expansion in a solid is usually small.

Particles in a liquid ___________ ___________________________ ___________________________; this stops the liquid expanding as much as a gas, but allows it to expand more than a solid.

_____________________________ _____________________________ _____________________________ _____________________________, so gases expand a lot when their temperature rises.

Warning! Students often write that when a substance is heated, “its particles expand”. You would get no marks for this! The particles don’t expand – they stay the same size. The substance itself expands, because its particles move farther apart.

Thermal expansion - uses and risks: Applications Thermometers: The liquid (mercury, or more commonly alcohol) in a thermometer _____________ when heated, and can be used to show the temperature: Bimetallic strips: Different metals expand by different amounts when heated. If strips of two different metals are welded/stuck together, their different amounts of expansion causes them to bend. This phenomenon can be used for temperature measurement, or for cutting off a circuit when it gets too hot.

A bimetallic strip thermometer (left). This strip is bent into a spiral. When it expands, the spiral starts to open out, and the pointer moves round. Dealing with Risks When large structures like bridges expand in hot weather, this could cause serious danger and damage: the bridge could bend or crack. The pictures below show ‘expansion joints’ in bridges: they give room for the bridge to expand safely.

The same applies to railway tracks. On the left is a track which has got hot, expanded and buckled (notice the derailed train in the background). It is important to include small gaps in the rails so this doesn’t happen.

4. Evaporation Describe evaporation in terms of the escape of more energetic molecules from the surface of a liquid.

Relate evaporation to the consequent cooling.

Demonstrate understanding of how temperature, surface area and air flow over a surface influence evaporation.

Evaporation can be explained by the kinetic molecular model of matter (matter is made of moving particles). Evaporation is a change of state of a ____________ into a ____________ at a temperature ____________ the boiling point of the liquid. It happens at the liquid ____________, where some of the ____________ -moving particles escape. (In a liquid, there is an average particle speed, but some particles will be faster than this and some slower.) This lowers the average kinetic energy of the particles in the liquid – so the liquid’s ____________ drops.

Factors which increase the rate of evaporation:

speed of molecule (m/s)

no. of molecules at a particular speed

Average speed

5. Melting and Boiling Describe melting and boiling in terms of energy input without a change in temperature.

Distinguish between boiling and evaporation.

Describe condensation and solidification.

State the meaning of melting point and boiling point.

Use the terms latent heat of vaporisation and latent heat of fusion and give a molecular interpretation of

latent heat. Changes of State ‘States of matter’ are the physical states in which matter can exist: solid, liquid and gas. You need to remember the words we use for the changes between states:

Changes of state can be explained by the kinetic molecular model of matter: Melting happens when the particles of a solid get enough ____________ to partly break free of their attractions. This happens if the solid is given enough heat to reach its melting point (melting temperature), for example 0°C for ice. Boiling happens when the particles of a liquid get enough energy to break free of their ____________

completely. This happens if the liquid is given enough heat to reach its boiling point (boiling temperature), for example, 100°C for water. Water is an unusual substance. Most liquids contract (get smaller) as they get colder and then freeze. But when water gets close to freezing, its particles actually get farther apart. That’s because in solid water (ice), the particles fit together in a particular arrangement which is relatively spaced out (see diagrams). That means ice is less dense than water, which has some important consequences for our planet… Boiling and Evaporation

Evaporation Boiling

Involves liquid turning into gas. Involves liquid turning into gas.

Happens at any temperature (as long as the substance is a liquid).

Happens throughout the liquid. Bubbles appear and rise to the surface. These bubbles are filled with the gas version of the liquid. (E.g. when water boils, the bubbles are full of water in the gas state.)

Heat has to enter the liquid from outside to make boiling happen.

Slow.

SOLIDIFIES/FREEZES

Latent Heat When you boil a liquid, its temperature doesn’t go above the boiling point until it has finished boiling. For example, while you are boiling water, the temperature of the water stays at 100°C until all the water has boiled to water vapour.

This may seem strange: you are putting heat energy into the liquid, yet its temperature does not rise. Where is the energy going? The heat energy is used to break the intermolecular attractions between the molecules of the liquid; after the liquid has turned to gas, this energy is stored in the gas as potential energy. (The molecules now have the potential to come back together again to form a liquid. If they do, the stored chemical energy will turn back into heat energy.) The same thing happens when a solid melts. For example, if you heat ice so that it melts, the temperature of the ice+water mixture will stay at 0°C until all the ice has melted.

This diagram shows the energy and temperature changes when a substance melts or boils. (Ek means kinetic energy of the particles; Ep means potential energy of the particles.) Below is a heating curve for water; a heating curve is a graph showing the temperature of a substance plotted against the amount of energy it has absorbed. You may also see a cooling curve, which shows the temperature when a substance cools down.

6. Behaviour of Gases

Describe qualitatively the pressure of a gas in terms of the motion of its molecules.

Describe qualitatively the effect of a change of temperature on the pressure of a gas at constant volume.

Describe qualitatively the effect of a change of temperature on the volume of a gas at constant pressure.

Relate the change in volume of a gas to change in pressure applied to the gas at constant temperature and use the equation p V = constant at constant temperature.

Why do gases exert a pressure?

What happens to the pressure when you increase the temperature (but keep the volume the same – say, by trapping the gas inside a strong box)?

Cool gas Hot gas

What happens to the volume when you increase the temperature (but keep the pressure the same – say, by keeping the same weight on top of the gas)?

Lower temp. Higher temp.

If you keep the temperature of a gas the same but change its pressure, the volume will change. Or if you change the volume, the pressure will change:

In a gas at constant temperature, the pressure (p) is inversely proportional to the volume (V): that means if the pressure increases the volume decreases, and if the pressure decreases the volume increases. The relationship looks like this:

3 Particle model of matter – Trilogy

STUDY: Not only should you be able to draw the particle model but you need to be able to describe the structure and bonding too. https://www.bbc.co.uk/bitesize/guides/z3gxdxs/revision/1

1.0 A teacher uses a tray filled with table tennis balls to model how particles are arranged in materials, as shown in Figure 1.

Figure 1

1.1 Initially the balls are arranged in a regular pattern as shown in Figure 1.

Which state of matter is best represented by the balls in Figure 1?

[1 mark]

Tick one box.

solid

liquid

gas

1.2 The teacher then moves the tray from side to side so that the table tennis balls are no longer in a regular pattern.

Which state of matter is now best represented by the balls?

[1 mark]

Tick one box.

solid

liquid

gas

https://www.bbc.co.uk/bitesize/guides/z3gxdxs/revision/1

TRY: https://phet.colorado.edu/sims/html/states-of-matter-basics/latest/states-of-matter-basics_en.html

1.3 The teacher next performs another demonstration by moving the tray more vigorously so that some of the balls jump out of the tray.

The teacher tells the students that the balls that have left the tray represent gas particles.

Which two processes could this demonstration represent?

[2 marks]

Tick two boxes.

boiling

condensing

evaporation

freezing

melting

1.4 Gases can be at different temperatures.

[1 mark]

Tick one box.

The temperature of a gas is related to

the average size of the particles

the average mass of the particles

the average kinetic energy of the particles

1.5 Figure 2 shows some of the gas particles in a balloon.

Figure 2

Describe the movement of the gas particles inside the balloon.

https://phet.colorado.edu/sims/html/states-of-matter-basics/latest/states-of-matter-basics_en.html

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

READ: https://www.bbc.co.uk/bitesize/guides/zbg7hyc/revision/1

TRY: https://quizlet.com/324947049/density-equations-flash-cards/

1.6 The gas in the balloon has a mass of 0.032 kg.

The balloon has a volume of 0.025 m3.

Calculate the density of the gas in the balloon.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Density of gas =____________________ kg/m3

https://www.bbc.co.uk/bitesize/guides/zbg7hyc/revision/1

https://quizlet.com/324947049/density-equations-flash-cards/

2.0 Figure 3 shows a fridge with a freezer compartment.

Figure 3

2.1 Energy is transferred to cool food when it is placed in the fridge.

Complete the sentence to describe how energy is transferred to cool the food.

[2 marks]

Energy is transferred from the

_________________ to the _______________.

This energy is then transferred to the _______________.

COMPLETE this table about the particle model of the three states of matter.

SOLID LIQUID GAS

Particle model diagram

Describe the arrangement of the atoms

Describe the movement of particles

Describe the bonds

Fixed shape?

Fixed volume?

food fridge surroundings

2.2 The fridge and freezer compartment contain water in three different states.

Use your knowledge of the particle model to explain the differences in how the particles are arranged in solids, liquids and gases.

Include in your answer any differences in how the particles move in each state of matter.

[6 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

WATCH: https://www.youtube.com/watch?v=HtnTgxu663U

Evaluate what you saw in the video.

How were the particles moving in the hot liquid compared to the cold liquid. Can you explain why this occurred, use your ideas about energy.

2.3 The temperature of the air inside the freezer compartment is –5 °C.

The temperature of the air inside the fridge is 5 °C

Explain why the particles in the freezer compartment move at a different speed than those in the main part of the fridge.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

3.0 A student used the apparatus in Figure 4 to compare the specific heat capacities of different metals. Figure 4

The student measured the time taken to increase the temperature of each material by 10 °C.

Figure 5 shows the student’s results.

Figure 5

Material

https://www.youtube.com/watch?v=HtnTgxu663U

REMIND YOUR SELF about the Specific Heat Capacity Required Practical.

Watch https://www.youtube.com/watch?v=loeRLKNeUsc

3.1 The student makes the following conclusion;

‘The specific heat capacity of concrete is five times greater than tin.’

Use data from the bar chart to decide if the student’s conclusion is correct.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Try: https://www.bbc.co.uk/bitesize/guides/zcpwrwx/revision/3

Write the equation four times in the space below, each time changing the subject of the equation.

Energy = Specific heat

capacity =

Mass = Change in

temperature =

3.2 The iron block had a mass of 1.023 kg.

The specific heat capacity of iron is 450 J / kg °C.

Calculate the energy transferred by the heater to increase the temperature of the iron block by 10 °C.

Use the correct equation from the physics equation sheet.

Give your answer to two significant figures.

[3 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Energy transferred = __________________ J

https://www.youtube.com/watch?v=loeRLKNeUsc

https://www.bbc.co.uk/bitesize/guides/zcpwrwx/revision/3

The student used the same apparatus to heat a 1 kg block of aluminium.

He recorded the temperature of the block as it was heated from room temperature.

The results are shown in Figure 6.

Figure 6

Time the immersion heater is switched on for in minutes

3.3 After how many minutes did the student record the incorrect temperature?

[1 mark]

Time = ______________ minutes

3.4 Draw the line of best fit for the points plotted in Figure 6.

[1 mark]

3.5 What was the temperature of the room?

[1 mark]

Temperature ________________ °C

3.6 Another student suggested repeating the experiment using a heater with a greater power.

Explain what effect this would have on the gradient of the graph the student drew.

[3 marks]

_____________________________________________________________________

__________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________



...............................................................................................................................................................

Recall the equation to calculate density.

.................................................................................................................................................


.................................................................................................................................................

What piece of equipment is used to measure area?

.................................................................................................................................................

What piece of equipment is used to measure mass?

.................................................................................................................................................

What piece of equipment is used to measure volume?

.................................................................................................................................................

Look at the blue cube. Write a method to calculate the density of this regular shaped object. Remember you

might need an additional bit of equipment.





then yes!

Look at the pebble in the measuring cylinder. Write a method to calculate the density of this irregular

shaped object. Remember you might need an additional bit of equipment.


An alternative method to calculate the density of an irregular object is depicted below. Briefly outline how

this method works.

..................................................................................................................................................................

..................................................................................................................................................................

..................................................................................................................................................................

..................................................................................................................................................................

Outline how to find the density of a liquid.

...........................................................................................

.......................................................................

...........................................................................................

.......................................................................

..................................................................................................................................................................

.................................................................................................................................................................

Find the area of the objects below:




then yes!


Specification Statement Revised RAG

Recall and apply the density = mass/volume equation to changes where mass is conserved

Recognise/draw simple diagrams to model the difference between solids, liquids and gases Explain the differences in density between the different states of matter in terms of the arrangement of

atoms or molecules

Use appropriate apparatus to make and record the measurements needed to determine the densities of regular and irregular solid objects and liquids

Describe how, when substances change state (melt, freeze, boil, evaporate, condense or sublimate), mass is conserved

Apply the specific heat capacity equation, which is given on the Physics equation sheet, to calculate the energy change involved when the temperature of a material changes

Interpret heating and cooling graphs that include changes of state Apply the equation, which is given on the Physics equation sheet, to calculate the energy change involved

in a change of state

Distinguish between specific heat capacity and specific latent heat

Explain how the motion of the molecules in a gas is related to both its temperature and its pressure

Explain qualitatively the relation between the temperature of a gas and its pressure at constant volume



key revision

Keywords

Solid Condense

Liquid Sublimate

Gas Freeze

Density Melt

Internal energy Boil

Specific heat capacity State of matter

Latent heat Gas pressure

Evaporate Kelvin


Density

Pressure

Kinetic theory and state changes

Temperature and gas calculations

http://www.bbc.co.uk/education/guides/zbg7hyc/revision

http://www.bbc.co.uk/education/guides/zrcmn39/revision/2

http://www.bbc.co.uk/education/guides/zgr2pv4/revision/1

http://www.bbc.co.uk/education/guides/zc4xsbk/revision/1


1. What is the equation for calculating density?

2. True or False: changes of state are physical changes?

3. What is the total kinetic and potential energy of all particles that make up a system known as?

4. Which three factors affect the increase in temperature of a substance?

5. What is the amount of energy required to raise the temperature of a substance by 1oC known as?

6. What is the energy needed for one Kg of a substance to change state without a change in temperature

known as?

7. Describe the motion of molecules of a gas.

8. What happens to the pressure exerted by a gas, held at constant volume, when the temperature is

increased?

Keyword Definition

Solid

Liquid

Gas

Density

Internal energy

Specific heat capacity

Latent heat

Evaporate

Condense

Sublimate

Freeze

Melt

Boil

State of matter

Gas pressure



137 How much mass a substance contains compared to it's volume is…

density

138 State the equation which links density, mass and volume

ρ m/v

139 Name the change of state when a liquid becomes a solid

freezing

140 Name the change of state when a solid becomes a liquid

melting

141 Name the change of state when a liquid becomes a gas

evaporation

142 Name the change of state when a gas becomes a liquid

condensation

143 Name the change of state when a solid becomes a gas (without passing through liquid form)

sublimation

144 Changes of state are caused by the amount of _________ a substance has

energy

145 State changes are examples of ___________ change

physical

146 Physical changes are ones which can be _____________

reversed

147 A change which creates new products and cannot be reversed is _________ change

chemical

148 The energy stored inside a system by the particles which make it up is known as ____________ energy

internal

149 What is internal energy? The total kinetic energy and potential energy of all the particles in a system

150 Energy stored within moving objects is __________

kinetic

151 Energy stored in particles because of their position is…?

potential energy

152 Particles wich are further apart have _________ potential energy

more

153 The energy needed to raise the temperature 1 kg of a material by 1ᵒC is the __________

specific heat capacity

154 The average kinetic energy of particles is known as the ___________

temperature

155 The amount of energy required to change the state of one kilogram of a substance with no change in temperature is the …?

specific latent heat

156 Latent heat of fusion is for changing…? solid to liquid

157 Latent heat of vaporisation is for changing….? liquid to vapour (gas)

158 Increasing temperature ______________ pressure in a gas if volume is constant

increases

159 The force exerted by gas on a surface as the particles collide with it is known as….?

gas pressure

160 State the units of density kg/m3

161 State the units of volume m3

162 Sketch the heating curve for water

163 Draw a particle diagram for a solid

164 Draw a particle diagram for a liquid

165 Draw a particle diagram for a gas

166 Why doesn't temperature increase during melting?

Energy is being used to weaken forces between particles

167 Why doesn't temperature increase during evaporation

Energy is being used to weaken forces between particles

168 Why does temperature of a substance increase as it is heated?

Particles gain more kinetic energy and temperature is a measure of kinetic energy

169 Particles are arranged regularly in a ….? solid

170 Particles are arranged randomly, but touching in a …?

liquid

171 Particles move around randomly in a ….? gas

TAKE CARE:

there

should be

no particle

sized gaps.

Science Faculty Physics 4: Atomic Structure Checklist

Atomic Structure check The structure

of an atom Atoms are very small, having a radius of about 1 × 10-10 metres.

The basic structure of an atom is a positively charged nucleus composed of both protons and neutrons surrounded by negatively charged electrons.

The radius of a nucleus is less than 1/10 000 of the radius of an atom. Most of the mass of an atom is concentrated in the nucleus.

The electrons are arranged at different distances from the nucleus (different energy levels). The electron arrangements may change with the absorption of electromagnetic radiation (move further from the nucleus; a higher energy level) or by the emission of electromagnetic radiation (move closer to the nucleus; a lower energy level).

In an atom the number of electrons is equal to the number of protons in the nucleus. Atoms have no overall electrical charge.

All atoms of a particular element have the same number of protons. The number of protons in an atom of an element is called its atomic number.

The total number of protons and neutrons in an atom is called its mass number.

Atoms of the same element can have different numbers of neutrons; these atoms are called isotopes of that element.

Atoms turn into positive ions if they lose one or more outer electron(s).

Students should be able to relate differences between isotopes to differences in conventional representations of their identities, charges and masses.

The development of the model of the atom

New experimental evidence may lead to a scientific model being changed or replaced.

Before the discovery of the electron, atoms were thought to be tiny spheres that could not be divided.

The discovery of the electron led to the plum pudding model of the atom. The model suggested that the atom is a ball of positive charge with negative electrons embedded in it.

The results from the alpha particle scattering experiment led to the conclusion that the mass of an atom was concentrated at the centre (nucleus) and that the nucleus was charged. This nuclear model replaced the plum pudding model.

Niels Bohr adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances. The theoretical calculations of Bohr agreed with experimental observations.

Later experiments led to the idea that the positive charge of any nucleus could be subdivided into a whole number of smaller particles, each particle having the same amount of positive charge. The name proton was given to these particles.

The experimental work of James Chadwick provided the evidence to show the existence of neutrons within the nucleus. This was about 20 years after the nucleus became an accepted scientific idea.

why the new evidence from the scattering experiment led to a change in the atomic model

the difference between the plum pudding model of the atom and the nuclear model of the atom.

Radioactive decay and

nuclear radiation

Some atomic nuclei are unstable. The nucleus gives out radiation as it changes to become more stable. This is a random process called radioactive decay.

Activity is the rate at which a source of unstable nuclei decays

Activity is measured in becquerel (Bq)

Count-rate is the number of decays recorded each second by a detector (eg Geiger-Muller tube).

The nuclear radiation emitted may be: • an alpha particle (α) – this consists of two neutrons and two protons, it is the same as a helium nucleus • a beta particle (β) – a high speed electron ejected from the nucleus as a neutron turns into a proton

• a gamma ray (γ) – electromagnetic radiation from the nucleus • a neutron (n).

Required knowledge of the properties of alpha particles, beta particles and gamma rays is limited to their penetration through materials, their range in air and ionising power.

Students should be able to apply their knowledge to the uses of radiation and evaluate the best sources of radiation to use in a given situation.

Nuclear equations

Nuclear equations are used to represent radioactive decay.

beta decay does not cause the mass of the nucleus to change but does cause the charge of the nucleus to increase.

Students should be able to use the names and symbols of common nuclei and particles to write balanced equations that show single alpha (α) and beta (β) decay. This is limited to balancing the atomic numbers and mass numbers.

The emission of a gamma ray does not cause the mass or the charge of the nucleus to change.

Half-lives and the random

nature of radioactive

decay

Radioactive decay is random.

The half-life of a radioactive isotope is the time it takes for the number of nuclei of the isotope in a sample to halve, or the time it takes for the count rate (or activity) from a sample containing the isotope to fall to half its initial level.

Explain the concept of half-life and how it is related to the random nature of radioactive decay.

determine the half-life of a radioactive isotope from given information.

Radioactive contamination

Radioactive contamination is the unwanted presence of materials containing radioactive atoms on other materials. The hazard from contamination is due to the decay of the contaminating atoms. The type of radiation emitted affects the level of hazard.

Irradiation is the process of exposing an object to nuclear radiation. The irradiated object does not become radioactive.

Students should be able to compare the hazards associated with contamination and irradiation.

Suitable precautions must be taken to protect against any hazard that the radioactive source used in the process of irradiation may present.

Students should understand that it is important for the findings of studies into the effects of radiation on humans to be published and shared with other scientists so that the findings can be checked by peer review.

Background radiation

Background radiation is around us all of the time. It comes from: • natural sources such as rocks and cosmic rays from space • man-made sources such as the fallout from nuclear weapons testing and nuclear accidents.

The level of background radiation and radiation dose may be affected by occupation/location.

Radiation dose is measured in sieverts (Sv)

1000 millisieverts (mSv) = 1 sievert (Sv)

Different half-lives of

radioactive isotopes

Radioactive isotopes have a very wide range of half-life values.

Students should be able to explain why the hazards associated with radioactive material differ according to the half-life involved.

Uses of nuclear

radiation

Nuclear radiations are used in medicine for the: • exploration of internal organs • control or destruction of unwanted tissue.

describe and evaluate the uses of nuclear radiations for exploration of internal organs, and for control or destruction of unwanted tissue

evaluate the perceived risks of using nuclear radiations in relation to given data and consequences.

Nuclear fission

Nuclear fission is the splitting of a large and unstable nucleus (eg uranium or plutonium).

Spontaneous fission is rare. Usually, for fission to occur the unstable nucleus must first absorb a neutron.

The nucleus undergoing fission splits into two smaller nuclei, roughly equal in size, and emits two or three neutrons plus gamma rays. Energy is released by the fission reaction.

All of the fission products have kinetic energy.

The neutrons may go on to start a chain reaction.

The chain reaction is controlled in a nuclear reactor to control the energy released. The explosion caused by a nuclear weapon is caused by an uncontrolled chain reaction.

draw/interpret diagrams representing nuclear fission and how a chain reaction may occur.

Nuclear fusion Nuclear fusion is the joining of two light nuclei to form a heavier nucleus. In this process some of the mass may be converted into the energy of radiation.

Complete this table about what you know about the different types of radiation

Key words

Half-life: ________________________________________________________________________________

Isotope: ________________________________________________________________________________

alpha beta gamma

Symbol

Mass …and therefore… Relative speed

Charge …and therefore… Ionisation

Stopped by…

uses

6-4 Atomic structure – Trilogy

Read: https://courses.lumenlearning.com/boundless-chemistry/chapter/the-structure-of-the-atom/

1.0 Figure 1 shows a helium atom.

Figure 1

1.1 Use the words in the box to label the diagram.

[2 marks]

electron neutron proton

1.2 An alpha particle is the same as the nucleus of a helium atom.

How is an alpha particle different from a helium atom?

[1 mark]

_____________________________________________________________________

_____________________________________________________________________

1.3 Complete the atomic symbol for helium to show helium’s atomic number and mass number.

[2 marks]

_____

He

_____

https://courses.lumenlearning.com/boundless-chemistry/chapter/the-structure-of-the-atom/

https://courses.lumenlearning.com/boundless-chemistry/chapter/the-structure-of-the-atom/

RECALL: what is the definition of half-life?

READ: http://www.gcsescience.com/prad17-measuring-half-life.htm

TRY: https://www.nobraintoosmall.co.nz/students/physics/NCEA_Level2/L2_Exam_Help/L2_collated_questions/pdfs/Atoms__half_life_q_and_a.pdf

The graph shows how the count rate from a sample of radioactive sodium-24 changes with time.

1.4 What time, in hours, does it take for the count rate to fall from 60 counts per second to 40 counts per second?

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

time = ____________ hours

1.5 What is the half-life of sodium-24?

[1 mark]

half-life = _____________ hours

http://www.gcsescience.com/prad17-measuring-half-life.htm

https://www.nobraintoosmall.co.nz/students/physics/NCEA_Level2/L2_Exam_Help/L2_collated_questions/pdfs/Atoms__half_life_q_and_a.pdf

https://www.nobraintoosmall.co.nz/students/physics/NCEA_Level2/L2_Exam_Help/L2_collated_questions/pdfs/Atoms__half_life_q_and_a.pdf

WATCH: https://www.youtube.com/watch?v=BH2bKONkvFc

2.0 The names of three types of radiation are given in List A. Some properties of these three types of radiation are given in List B.

2.1 Draw one line from each type of radiation in List A to its correct property in List B.

[3 marks]

List A

Type of

radiation

List B

Property of radiation

will pass through paper but is stopped by thin metal

alpha

has the shortest range in air

beta

will not harm human cells

gamma

is very weakly ionising

2.2 Complete the following sentences using the words from the box.

[4 marks]

The most penetrating type of radiation is ___________ .

The type of radiation with the greatest charge is ____________ .

The type of radiation with the greatest range in air is _________ .

The two types of radiation that have no charge are __________and _________.

alpha beta gamma proton neutron

https://www.youtube.com/watch?v=BH2bKONkvFc

3.0 The discovery of the electron led to the plum pudding model to explain the structure of the atom.

The results from the alpha particle scattering experiment led to

the plum pudding model being replaced by the nuclear model.

TOP TIP: In the exam if you are asked to compare two things or describe the similarities and differences. Draw up a table to lay out your answer clearly and make sure you have enough points to make sure you gain all the marks.

And DON’T BOTHER writing the same thing but in reverse. E.g Nuclear model has shells, plum pudding does not have shells, you will only score 1 mark for this

3.1 Describe the differences between the two models of the atom.

[6 marks]

KEY WORD: What is the definitions of an isotope? Write it in the space below.

4.0 There are many isotopes of the element technetium (Tc).

4.1 What do the nuclei of different technetium isotopes have in common?

[1 mark]

_____________________________________________________________________

_____________________________________________________________________

Plum pudding Nuclear model

TRY: https://www.bbc.co.uk/bitesize/guides/zq3d6yc/revision/4

4.2 The isotope technetium-99 is produced when a nucleus of a molybdenum-99 decays; it emits radiation when it decays.

Mo Tc + Radiation

What type of radiation is emitted by molybdenum-99? ______________

[2 marks]

Give a reason for your answer.

_____________________________________________________________________

_____________________________________________________________________

4.3 Technetium-99 has a short half-life and emits gamma radiation.

What is meant by the term ‘half-life’?

[1 mark]

_____________________________________________________________________

4.4 Technetium-99 is used by doctors as a medical tracer. In hospitals it is produced inside a technetium generator by the decay of molybdenum-99 nuclei.

The graph below shows how the number of nuclei in a sample of molybdenum-99 changes with time as the nuclei decay.

Time in days

https://www.bbc.co.uk/bitesize/guides/zq3d6yc/revision/4

A technetium generator will continue to produce sufficient technetium-99 until three half-lives have passed.

After how many days should the technetium generator be replaced?

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Number of days = _____________

4.5 A doctor claims that after 13 days the technetium generator will be safe to dispose of.

Calculate the number of molybdenum nuclei remaining after 13 days, and comment on whether it would be safe to dispose of.

[6 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

number of molybdenum nuclei remaining = _____________

Safety _______________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________



Recognise expressions given in standard form Relate differences between isotopes to differences in conventional representations of their identities,

charges and masses

Show an understanding of why and describe how scientific methods and theories develop over time

Describe why the new evidence from the scattering experiment led to a change in the atomic model

Describe the difference between the plum pudding model of the atom and the nuclear model of the atom Recall properties of alpha particles, beta particles and gamma rays is limited to their penetration through

materials, their range in air and ionising power

Apply knowledge to the uses of radiation and evaluate the best sources of radiation to use in a given situation

Use the names and symbols of common nuclei and particles to write balanced equations that show single alpha (α) and beta (β) decay

Explain the concept of half-life and how it is related to the random nature of radioactive decay

Determine the half-life of a radioactive isotope from given information (HT only) Calculate the net decline, expressed as a ratio, in a radioactive emission after a given number of

half-lives

Compare the hazards associated with contamination and irradiation Understand that it is important for the findings of studies into the effects of radiation on humans to be

published and shared with other scientists so that the findings can be checked by peer review



key revision

Keywords

Alpha Irradiation

Beta Contamination

Gamma Nuclear model

Geiger counter Plumb pudding

Ionising Half life

Penetration Background radiation

Keyword Definition

Alpha

Beta

Properties of radiation


Atomic structure and isotopes

Uses and hazards of radiation

http://www.bbc.co.uk/education/guides/z44xsbk/revision

http://www.bbc.co.uk/education/guides/z996fg8/revision/1

http://www.bbc.co.uk/education/guides/zkktyrd/revision


1. What happens to an atom when it has an outer electron removed (e.g. by ionising radiation)

2. What is the name given to the process when radiation is released as an unstable nucleus becomes more

stable?

3. What is radioactivity measured in?

4. What is an alpha particle?

5. What is a beta particle?

6. What change takes place in a nucleus when a beta particle is emitted?

7. What electromagnetic radiation can be released from the nucleus of a radioactive sample?

8. How is an alpha particle represented in nuclear equations?

9. How is a beta particle represented in nuclear equations?

10. What is the time taken for the number of nuclei of an isotope in a sample to halve known as?

11. What is the presence of radioactive materials on or in other objects known as?

12. What is the process of exposing an object to nuclear radiation without causing it to become radioactive

known as?

Gamma

Geiger counter

Ionising

Penetration

Irradiation

Contamination

Nuclear model

Plumb pudding

Half life

Background radiation

Grade 5

Radiation and Half-life Worksheet

1. Where does nuclear radiation come from?

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

2. What are alpha particles made of?

……………………………………………………………………………………………………………

3. What are the properties of gamma radiation?

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

4. Complete the following nuclear decay equations. Add the mass numbers and atomic numbers of

the daughter element (shown as X).

5. A student is given a low-level radioactive source, but the label has gone missing from the lead-

lined box it is kept in. Design an experiment to find out whether the source is an alpha, beta or

gamma emitter using a Geiger-counter and a range of materials.

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

6. Explain what is meant by ionizing radiation.

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

7. Explain how ionizing radiation can affect living cells.

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

8. Gamma radiation may be used to treat cancer. The diagram below shows many gamma sources

directed at a single point. What is the advantage of this method compared with using a single

beam?

…………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

9. Why is gamma radiation used as a tracer in the body rather than alpha radiation?

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

10. What is half-life?

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

11. Use the graph to calculate the half life of a sample.

Half-life= ………………

12. Carbon-14 has a half-life of 5,700 years. If a sample of freshly cut wood has a count rate of 10

counts per minute, and a second piece of wood has a count rate of

2.5 counts per minute, how old is the second piece of wood?

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

……………………………………………………………………………………………………………

13. Would long or short half-life materials be appropriate in the following situations?

long or short half-

life? reason

smoke alarm

fuel for nuclear power

gamma knife for use

in hospital

radioactive source for

use in school

co

un

ts p

er

min

ute

time (days)



172 Define atom The smallest part of an element that can exist.

173 All substances are made up of…? atoms

174 The radius of an atom is …? 0.1 nm (1 x 1010 m)

175 The overall charge on an atom is… zero/neutral

176 Define element Contains only one type of atom

177 Substances found in the periodic table are…? elements

178 Approximately how many elements are there? 100

179 Define isotope An atom of the same element with different numbers of neutrons

180 Define radioactive decay An unstable nucleus changes to become more stabe and gives out radiation

181 We cannot predict when a given atom will decay, this means that radioactive deacy is ….?

random

182 Define activity Rate at which decay occurs

183 What are the units of activity? Becquerels (Bq)

184 Define count rate Number of decays recorded each second by a Geiger-Muller tube

185 Defne half life The time taken for number of radioactive nuclei in a sample to halve OR time taken for count rate (or activity) from a sample to fall to half its initial value

186 Define contamination The unwanted presence of materials containing radioactive atoms

187 Define irradiation When an object is exposed to radiation

188 Does an irradiatied object become radioactive itself?

no

189 The process of radiation removing electrons from atoms to form ions is called…?

ionisation

190 If ionisation happens in DNA it can cause ___________ which may result in ____________

mutations, cancer

191 Define peer review Checking of scientific results by other scientific experts

192 Define mass number The total number of protons and neutrons in an atom

193 Define atomic number The number of protons in an atom (number of electrons is the same in a neutral atom)

194 Electrons in atoms are located in ___________ energy levels

195 Absorption of radiation by an atom may result in ____________ moving to a ________________ energy level

electrons, higher

196 Emission of radiation from an atom may lead to _____________ moving to a ______________ energy level

electrons, lower

197 Who came up with the Plumb Pudding model of the atom

J J Thompson

198 Describe the Plumb Pudding model of the atom

A ball of positive charge with negative electrons embedded in it

199 Was the Plumb Pudding model correct? no

200 What experiment did Rutherford do? Alpha particle scattering

201 What did Rutherford's experiment reveal? Atoms have a central area of positive charge with electrons surrounding it

202 Who discovered that electrons are located in energy levels?

Niels Bohr

203 What did Jame Chadwick discover about the atom?

That the nucleus contains neutrons as well as protons

204 What did John Dalton contribute to our understanding of atomic theory?

Matter is made up of descrete, spherical particles, known as atoms

205 Name the three subatomic particles proton, neutron, electron

206 Which particles are located in the atoms nucleus

protons, neutrons

207 What is the charge of each subatomic particle? proton +1, neutron 0, electron -1

208 What is the mass of each subatomic particle? proton 1, neutron 1, elecrton ≈ 0

209 Name the three types of radiation alpha, beta and gamma

210 What is an alpha particle? two protons and two neutrons

211 What is a beta particle? an electron

212 What is gamma radiation? electromagnetic wave (NOT a particle)

213 What is the range of alpha radiation in air? short - 5 cm in air

214 What is the range of gamma radiation in air? unlimited in air

215 What's the range of beta radiation in air? medium - about 1 m

216 What will absorb (stop) alpha radiation? paper/skin

217 What will absorb (stop) beta radiation? about 5 mm aluminium

218 What will absorb (stop) gamma radiation? several centimetres of lead

219 What is the ionising power of alpha radiation? very high

220 What is the ionising power of beta radiation? medium

221 What is the ionising power of gamma radiation?

low

222 What is meant by the ionising power of radiation?

how likely it is to ionise atoms which it comes into contact with

223 How does alpha decay alter the mass number of the parent nucleus?

decreases by 4

224 How does alpha decay alter the atomic number of the parent nucleus?

decreases by 2

225 How does beta decay alter the mass number of the parent nucleus?

stays the same

226 How does beta decay alter the atomic number of the parent nucleus?

increases by 1

227 How does gamma radiation alter the mass and atomic number of the parent nucleus

unchanged (energy is released as the particles in the nucleus reorganise to a lower energy arrangement)

Science Faculty Physics 5: Forces Checklist

Forces RAG


Scalar and vector

quantities

Scalar quantities have magnitude only.

Vector quantities have magnitude and an associated direction.

A vector quantity may be represented by an arrow. The length of the arrow represents the magnitude, and the direction of the arrow the direction of the vector quantity.

Contact and non-contact

forces

A force is a push or pull that acts on an object due to the interaction with another object. All forces between objects are either: • contact forces – the objects are physically touching • non-contact forces – the objects are physically separated.

Examples of contact forces include friction, air resistance, tension and normal contact force.

Examples of non-contact forces are gravitational force, electrostatic force and magnetic force.

Force is a vector quantity.

Students should be able to describe the interaction between pairs of objects which produce a force on each object. The forces to be represented as vectors.

Gravity Weight is the force acting on an object due to gravity. The force of gravity close to the Earth is due to the gravitational field around the Earth.

The weight of an object depends on the gravitational field strength at the point where the object is.

Recall and apply weight = mass × gravitational field strength equation.

The weight of an object may be considered to act at a single point referred to as the object’s ‘centre of mass’.

The weight of an object and the mass of an object are directly proportional.

Resultant forces

A number of forces acting on an object may be replaced by a single force that has the same effect as all the original forces acting together. This single force is called the resultant force.

Students should be able to calculate the resultant of two forces that act in a straight line.

describe examples of the forces acting on an isolated object or system

Use free body diagrams to describe qualitatively examples where several forces lead to a resultant force on an object, including balanced forces when the resultant force is zero.

A single force can be resolved into two components acting at right angles to each other. The two component forces together have the same effect as the single force.

Students should be able to use vector diagrams to illustrate resolution of forces, equilibrium situations and determine the resultant of two forces, to include both magnitude and direction (scale drawings only).

Distance and displacement

Distance is how far an object moves and does not involve direction. It is a scalar quantity.

Displacement includes both the distance an object moves, measured in a straight line from the start point to the finish point and the direction of that straight line. Displacement is a vector quantity.

Express a displacement in terms of both the magnitude and direction.

Speed Speed does not involve direction. Speed is a scalar quantity.

The speed of a moving object is rarely constant. When people walk, run or travel in a car their speed is constantly changing.

The speed at which a person can walk, run or cycle depends on many factors including: age, terrain, fitness and distance travelled. Typical values may be taken as: walking 1.5 m/s; running 3 m/s; cycling 6 m/s.

Students should be able to recall typical values of speed for a person walking, running and cycling as well as the typical values of speed for different types of transportation systems

It is not only moving objects that have varying speed. The speed of sound and the speed of the wind also vary.

A typical value for the speed of sound in air is 330 m/s.

Students should be able to make measurements of distance and time and then calculate speeds of objects.

Students should be able to recall and apply s = v t equation.

Students should be able to calculate average speed for non-uniform motion.

Velocity The velocity of an object is its speed in a given direction. Velocity is a vector quantity.

Students should be able to explain the vector–scalar distinction as it applies to displacement, distance, velocity and speed.

The distance–

time relationship

If an object moves along a straight line, the distance travelled can be represented by a distance–time graph.

The speed of an object can be calculated from the gradient of its distance–time graph.

Students should be able to draw distance–time graphs from measurements and extract and interpret lines and slopes of distance–time graphs, translating information between graphical and numerical form.

Students should be able to determine speed from a distance–time graph.

If an object is accelerating, its speed at any particular time can be determined by drawing a tangent and measuring the gradient of the distance–time graph at that time.

Acceleration Students should be able to recall and apply acceleration = change in velocity/time taken equation.

An object that slows down is decelerating.

The acceleration of an object can be calculated from the gradient of a velocity–time graph.

draw velocity–time graphs from measurements and interpret lines and slopes to determine acceleration

Students should be able to apply final velocity2-initial velocity2 = 2 × acceleration × distance equation which is given on the Physics equation sheet.

Newton's First Law

If the resultant force acting on an object is zero and: • the object is stationary, the object remains stationary • the object is moving, the object continues to move at the same speed and in the same direction. So the object continues to move at the same velocity.

So, when a vehicle travels at a steady speed the resistive forces balance the driving force.

So, the velocity (speed and/or direction) of an object will only change if a resultant force is acting on the object.

Students should be able to apply Newton’s First Law to explain the motion of objects moving with a uniform velocity and objects where the speed and/or direction changes.

Newton's Second Law

The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.

Students should be able to recall and apply F=ma equation.

Students should be able to estimate the speed, accelerations and forces involved in large accelerations for everyday road transport.


investigate the effect of varying the force on the acceleration of an object of constant mass, and the effect of varying the mass of an object on the acceleration produced by a constant force.

Newton's Third Law

Whenever two objects interact, the forces they exert on each other are equal and opposite.

Students should be able to apply Newton’s Third Law to examples of equilibrium situations.

Forces and breaking

The stopping distance of a vehicle is the sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance). For a given braking force the greater the speed of the vehicle, the greater the stopping distance.

Reaction times vary from person to person. Typical values range from 0.2 s to 0.9 s.

driver’s reaction time can be affected by tiredness, drugs and alcohol. Distractions may also affect a driver’s ability to react.

explain methods used to measure human reaction times and recall typical results

interpret and evaluate measurements from simple methods to measure the different reaction times of students

evaluate the effect of various factors on thinking distance based on given data.

Factors affecting braking distance

The braking distance of a vehicle can be affected by adverse road and weather conditions and poor condition of the vehicle.

Adverse road conditions include wet or icy conditions. Poor condition of the vehicle is limited to the vehicle's brakes or tyres.

explain the factors which affect the distance required for road transport vehicles to come to rest in emergencies, and the implications for safety

estimate how the distance required for road vehicles to stop in an emergency varies over a range of typical speeds.

When a force is applied to the brakes of a vehicle, work done by the friction force between the brakes and the wheel reduces the kinetic energy of the vehicle and the temperature of the brakes increases.

The greater the speed of a vehicle the greater the braking force needed to stop the vehicle in a certain distance.

The greater the braking force the greater the deceleration of the vehicle. Large decelerations may lead to brakes overheating and/or loss of control.

estimate the forces involved in the deceleration of road vehicles in typical situations on a public road.

explain the dangers caused by large decelerations

Momentum is a property

of moving objects

Students should be able to recall and apply momentum = mass × velocity equation.

Conservation of

momentum

In a closed system, the total momentum before an event is equal to the total momentum after the event.

describe and explain examples of momentum in an event, such as a collision

Forces

6-5 Forces – Trilogy

1.0 The distance taken for a car to stop after an emergency depends on two things:

The thinking distance: how far the car travels while the driver processes the information.

The braking distance: how far the car travels after the driver presses the break.

1.1 Each distance is affected by different factors.

Tick the boxes to show whether each factor affects the thinking distance, the braking distance or both.

[2 marks]

Factor Thinking distance

Braking distance

Both

Speed of car

Water on road

Driver’s tiredness

Driver’s alcohol consumption

Condition of car’s brakes

Read and try the equations: https://mathsmadeeasy.co.uk/gcse-maths-revision/velocity-time-graphs-gcse-revision-

and-worksheets/

What is happening at each of these points on the graph?

_________________________________ ____________________________ ____________________________

_________________________________ ____________________________ ____________________________

https://mathsmadeeasy.co.uk/gcse-maths-revision/velocity-time-graphs-gcse-revision-and-worksheets/

https://mathsmadeeasy.co.uk/gcse-maths-revision/velocity-time-graphs-gcse-revision-and-worksheets/

1.2 Figure 1 shows part of a displacement-time graph of a car journey.

Figure 1

Complete the gaps with letters from the diagram.

[4 marks]

The car was moving forwards between ____ and ____.

The car was stationary between ____ and ____.

The car is moving slowest between ____ and ____.

The car was moving backwards between ____ and ____.

READ: https://www.grc.nasa.gov/www/BGH/Images/vectors.gif

Make a list of vectors and scalars.

Vectors Scalars

Displacement (m)

Time (s)

https://www.grc.nasa.gov/www/BGH/Images/vectors.gif

1.3 What is the difference between speed and velocity?

Put ticks in the boxes.

[2 marks]

Speed Velocity

Has size

Has direction

Scalar

Vector

Read and try https://www.bbc.co.uk/bitesize/guides/z3bqtfr/revision/4

V =

W =

X =

Y =

Z =

1.4 On the axes below, draw a velocity-time graph for a car that:

Moves at constant velocity

Slows down

Stops

[3 marks]

Velocity (m/s)

Time (s)

V

W X

Y

Z

https://www.bbc.co.uk/bitesize/guides/z3bqtfr/revision/4

Required Practical

Hooke’s Law

What did Hooke discover?

• the more force that was put on materials the more they __________________

• With some materials they also extended in a regular way

-eg. if the force was __________________ so did the extension

• this was true as long as their __________________ __________________ was not exceeded

What is the elastic limit?

• The material no longer shows elastic __________________

-ie does not return to __________________ size when stretching force is __________________

__________________

-i.e. is __________________ or __________________ than __________________

• The material is __________________ as the above effects are caused by __________________ of some

atomic __________________

Since Force is proportional to extension Hookes Law could be put as

Where F is the applied force in

__________________

x is the extension in __________________

Or if k is the __________________ constant F=kx

What does k mean in F=kx?

• k is called the __________________ constant and is a measure of the __________________ of the

__________________ or material

• It has units of __________________ (newtons per metre)

• The __________________ the k the __________________ the spring

• Materials with a __________________ k need a __________________ force to for a given

__________________

Example

• A spring is 0.38m long.

• When it is pulled by a force of 2.0 N, it stretches to 0.42 m.

• What is the spring constant? (Assume the spring behaves elastically.)

xF

2.0 A student wants to measure the spring constant of a spring. Figure 2

The equipment she uses is shown in Figure 2.

The scale measures distance in cm.

2.1 Explain why the mark for 0 cm is slightly below the top of the spring in the Figure 2.

[1 mark]

__________________________________________________________

__________________________________________________________

2.2 As the student carries out the experiment, her head moves slightly up and down when taking readings.

State the type of error this movement would have caused.

[1 mark]

__________________________________________________________

2.3 How does the pointer make the measurement of length more accurate?

[1 mark]

_____________________________________________________________________

_____________________________________________________________________

2.4 Explain how the student could use the equipment in Figure 2 to measure the spring constant of the spring.

[4 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

In the question below, highlight the words that give you a clue as to what the equation may be. Write it in the space below.

2.5 The student found that the spring constant of the spring was 15.6 N/m.

Calculate the extension of the spring if the energy stored in it was 1.95 J.

Give your answer to 2 significant figures.

[3 marks]

Extension = _________ cm

State Newtons Laws, write them in the box below.

Newtons first Law

Newtons second Law

Newtons third Law

3.0 Figure 3 shows a person using a device called a jetpack. Water is forced downwards from the jetpack and produces an upwards force on the person.

Figure 3

3.1 Explain why the jetpack moves upwards when water is forced downwards.

Include reference to the relevant law of physics in your answer.

[3 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

WRITE: all of the equations to know with acceleration and velocity in the space below.

WATCH: https://www.youtube.com/watch?v=WJN_F3PYp58

3.2 Read the following information.

Combined mass of jetpack and person 84 kg

Upwards force from water 1900 N

Starting velocity 0.0 m/s

Acceleration due to gravity, g 9.8 m/s2

Calculate the maximum speed the person with the jetpack reaches after moving 5 m upwards.

In your answer:

Use two significant figures at each step in your calculation. Show your working.

[6 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

______________________________________________Maximum velocity = ________ m/s

Figure 3

https://www.youtube.com/watch?v=WJN_F3PYp58



Describe the difference between scalar and vector quantities

Discuss the link between weight, mass and gravity

Calculate resultant forces (and resolve forces HT only)

Calculate work done

Describe and interpret the Springs investigation (RPA)

Calculate moments

Calculate pressure (and how it varies in liquids HT only)

Calculate an object’s speed, velocity and acceleration

Interpret distance-time graphs

Interpret velocity-time graphs

Describe and interpret the F=ma investigation (RPA)

dentify situations where Newton’s third law is evident

Discuss factors affecting Stopping distance and carry out calculations

Calculate momentum and change in momentum (HT only)



key revision

Keywords

Vector Displacement

Scalar Velocity

Weight Acceleration

Resultant force Friction

Work Air resistance

Elastic Terminal velocity

Inelastic Stopping distance

Deformed Reaction time

Line of proportionality Braking distance

Moment Free body diagram

Level Equilibrium

Gears Up thrust

Pressure Inertia

Fluid Inertial mass

Atmosphere Momentum

Conservation of momentum

Speed, Velocity & Acceleration


Falling and Stopping Forces & momentum

Forces

https://www.bbc.co.uk/education/guides/z3bqtfr/revision/1

https://www.bbc.co.uk/education/guides/zv3j6sg/revision/1

https://www.bbc.co.uk/education/guides/zyydmp3/revision/1

https://www.bbc.co.uk/education/guides/zff82hv/revision

Keyword Definition

Vector

Scalar

Weight

Resultant force

Work

Elastic

Inelastic

Deformed

Line of proportionality

Moment

Level

Gears

Pressure

Fluid

Atmosphere

Displacement

Velocity

Acceleration

Friction

Air resistance

Terminal velocity

Stopping distance

Reaction time

Braking distance

Free body diagram

Equilibrium

Up thrust


1. Give examples of contact forces

2. Give examples of non-contact forces

3. A runner runs a 400 m race around a track. If he finishes at the same place as he started, what is his final

distance and displacement?

4. Abi swam 50 m in 21212 minutes. Calculate her average speed in m/s.

5. Car A accelerates from 10 m/s to 40 m/s in 6 s. Car B accelerates from 20 m/s to 30 m/s in 5 s. Determine

which car has the greater acceleration.

6. Explain why a ball accelerates when you drop it.

7. Why does a feather fall more slowly than a ball?

8. Why are the units for acceleration different from those for velocity?

9. An apple drops from a tree and falls 2.5 m to the ground. What is its speed when it hits the ground? Assume

g = 9.8 m/s2 and ignore air resistance.

10. An astronaut on the Moon feels much lighter than on Earth. Have they lost weight?

11. Is it always true that when all the forces on an object balance out it will be stationary?

12. Explain why there is a zero resultant force in the horizontal direction for a bicycle being pedalled along a

level road at steady speed in a straight line.

13. Draw a free-body diagram for an aeroplane flying horizontally with positive acceleration.

14. HT - Two forces act on an object. One force is 5 N to the right and the other force is 12 N upwards. Draw a

scale diagram to find the magnitude and direction of the resultant force.

15. HT - Another form of mass is gravitational mass. Suggest what the difference is between gravitational mass

and inertial mass.

16. HT - Calculate the momentum of a car with a mass of 1000 kg travelling at 20 m/s.

17. A spring has an extension of 0.08 m when it is stretched by a force of 4 N. What is its spring constant?

18. Explain what would happen if a roller coaster had a negative acceleration and the passengers weren’t

wearing restraints.

Grade 5

Speed

1. Write down the formula for calculating average speed.

2. How long does it take someone to walk 3km, at an average speed of 2m/s?

3. What is the difference between displacement and distance?

4. Draw a distance-time graph to show the following car journey: travel at a constant speed

of 10m/s for 30s, stopping for 20s, constant speed of 20m/s for 10s, then deceleration to

stop over the next 40s.

4a. What is the average speed over the first minute of the journey?

5. You leave home and walk down the road at a constant speed, then you stop to check if

you have your phone, realising you have left it at home you run back to get it. Draw a

displacement-time graph for this journey.

6. What is the difference between speed and velocity?

Acceleration

1. What is acceleration? Write down the formula for calculating acceleration.

2. A cyclist can accelerate from 4m/s to 16m/s in 3s. What is her acceleration?

3. Look at the velocity-time graph below:

Label the parts of the graph where the object is …

a. stationary

b. moving at a constant speed

c. accelerating

d. decelerating

e. changing direction

3f. What is the acceleration at 70s?

3g. What is the acceleration at 100s?

-40

-30

-20

-10

0

10

20

30

40

50

60

70

0 20 40 60 80 100 120 140 160

Vel

oci

ty (

m/s

)

Time (s)

Forces

1. What is an ‘interaction pair’ of forces? Give an example.

………………………………………………………………………………………………………………………………………………

……………………………………………………………………………………………………………………..

2. The person is pushing the book, but it is not moving.

Identify 4 forces and draw arrows to represent their

size and direction.

3. What is friction? Describe 3 types of friction.

………………………………………………………………………………………………………………………………………………

…………………………………………………………………………….......…………………………………………………………

…………………………………………………………………………………………………………..

4. What is a resultant force?

……….......…………………………………………………………………………………………………………………..

……….......……………………………………………………………………………………………………………………

5. Identify all the forces acting on the car. What is the resultant force if the car is moving

forwards at a steady speed?

Momentum

1. Identify 3 forces acting on the rocket when it accelerates upwards.

What can you say about the relative size of the forces?

2. How can you calculate the momentum of an object if you know its mass and velocity?

3. What are the units of momentum?

4. How is the change in momentum of an object related to the forces acting on it?

5. A football weighing 0.5kg is moving at 20m/s. A footballer stops the ball with a force of

20N. How long is this force acting for?

6. Explain how air bags, seat belts and crumple zones reduce the risk of serious injury in a

car crash.

………………………………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………………………………

……………………………………………………………………………

These questions and answers are fundamental to understanding this topic. Use these

questions and answers to practice and revise from. Make que cards or simply cover the

right hand side of the page and reveal each answer.

228 A value with magnitude only is a ________? scalar

229

A value with magnitude and direction is a

____________? vector

230

Distance an speed are examples of _________

quantities scalar

231

Force, displacement and velocity are examples of

__________ quantities vector

232 What is a contact force? A force between two object which are touching

233 What ia a non-contact force?

A force between objects which are separated by

space.

234 Give two examples of contact forces e.g. friction, air resistance

235 List three non-contact forces gravitational, electrostatic, magnetic

236 Define weight The force ofgravity acting on an object's mass

237 What device is used to measure weight? A newtonmeter

238

What is the name of the single point at which an

object's mass appears to act? centre of mass

239 The center of mas of an object is…

the single point at which the objects weight appears

to act.

240

The single force which has the same effect as the

combination of all the different forces acting on an

object is the ______________ _______________. resultant force

241 Work is done when an object is …. … moved through a distance

242

Moving objects with mass are said to have

__________? momentum

243 State the law of conservation of momentum

In a closed system the total momentum before an

event is equal to the total momentum after an event.

244

State the equation which links gravitaional field

strength, mass and weight W=mg

245

State the equation which links distance, force and

work done W=Fs

246

State the equation which links extension, force and

spring constant F=ke

247

State the equation which links distance, speed and

time s=vt

248

State the equation which links acceleration, change

in velocity and time taken a Δv/t

249

State the equation which links acceleration, mass

and resultant force F = ma

250

State the equation which links mass, momentum

and velocity ρ = mv

251 What is the unit of weight? Newtons (N)

252 What is the unit of mass? kilograms (kg)

253 What is unit of gravitational field strength? newtons per kilogram (N/kg)

254 What is the unit of work done? Joules (J)

255 What is the unit of force? Newtons (N)

256 What is the unit of distance? meters (m)

257 What is the unit of the spring constant? Newtons per meter (N/m)

258 What is the unit of the spring extension? Metres (m)

259 What is the unit of speed or velocity? metres per secons (m/s)

260 What are the units of acceleration? metres per second squared (m/s2)

262

When a spring is stretched and can then return to

its original length it is known as __________

_______________ elastic deformation or elastic behaviour

263

When a spring is stretched and its length is

permanently altered it is known as ___________

____________ Inelastic deformation or inelastic behaviour

264 The limit of proportionallity of a spring is…

the length a spring can be stretched to before it no

longer returns to its original length

265

Sketch the Force (y) -Extension (x) curve for

stretching a spring from no force to beyond its

elastic limit. teacher to draw on board…

266

The stopping distance of a vehicle is the sum of the

….. thinking and breaking distances

267

The distance a vehicle travels while the driver is

reacting is the … thinking distance

268

The distance a vehicle travels which the driver is

breaking is the … breaking distance

269 Reaction time is… the time it takes a driver to react

270 A typical reaction time is … 0.2-0.9 s

271 Factors which influence reaction time are… tiredness, drug, alcohol, distractions

272 Fctors which affect breaking distance are … weather conditions, conditions of breaks and tyres

273 Both thinking and breaking distance are affected by

speed of vehicle

which factor?

274

The greater the speed of a vehicle, the _________

the force required to stop the vehicle greater

275

The distance and object moves and the direction in

which it moves is known as the _________ displacement

276

The speed of an object in a particular derection is

its ___________ velocity

277

The change of an objects speed in a given time is

the _________ acceleration

280

On a distance time graph a straight line

represents… constant speed

281

On a distance time graph a upward curve

represents… acceleration

282

On a distance time graph a curved line becoming

horizontal represents… decelleration

283

On a distance time graph a horizontal line

represents… stationary

284

On a distance time graph the gradient is used to

calculate the … speed or velocity

292 A typical walking speed is … 1.5 m/s

293 A typical running speed is … 3 m/s

294 A typical cycling speed is … 6 m/s

295 Sound in air travels at … 330 m/s

296 State Newton's First Law

The velocity of an object will only change if a resultant

force is acting on the object.

297 f balanced forces act on a moving object it will … continue to travel at a constant speed

298

If balanced forces act on a stationary object it will

… remain stationary

299 State Newton's Second Law

Force = mass x acceleration (The acceleration of an

object is proportional to the resultant force acting on

the object, and inversley proportional to the mass of

the object)

300 State Newton's Third Law

Whenever two objects interact, the forces they exert

on each other are equal and opposite

Science Faculty Physics 6: Waves Checklist

Electromagnetic spectrum RAG foundation higher triple

Electromagnetic waves are transverse waves that transfer energy from the source of the waves to an absorber.

Electromagnetic waves form a continuous spectrum and all types of electromagnetic wave travel at the same velocity through a vacuum (space) or air.

The waves that form the electromagnetic spectrum are grouped in terms of their wavelength and their frequency. Going from long to short wavelength (or from low to high frequency) the groups are: radio, microwave, infrared, visible light (red to violet), ultraviolet, Xrays and gamma rays.

Students should be able to give examples that illustrate the transfer of energy by electromagnetic waves.

investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface.

Changes in atoms and the nuclei of atoms can result in electromagnetic waves being generated or absorbed over a wide frequency range. Gamma rays originate from changes in the nucleus of an atom.

Ultraviolet waves, X-rays and gamma rays can have hazardous effects on human body tissue. The effects depend on the type of radiation and the size of the dose. Radiation dose (in sieverts) is a measure of the risk of harm resulting from an exposure of the body to the radiation.

1000 millisieverts (mSv) = 1 sievert (Sv)

Students should be able to draw conclusions from given data about the risks and consequences of exposure to radiation.

Ultraviolet waves can cause skin to age prematurely and increase the risk of skin cancer. X-rays and gamma rays are ionising radiation that can cause the mutation of genes and cancer.

Electromagnetic waves have many practical applications. For example: • radio waves – television and radio • microwaves – satellite communications, cooking food • infrared – electrical heaters, cooking food, infrared cameras • visible light – fibre optic communications • ultraviolet – energy efficient lamps, sun tanning • X-rays and gamma rays – medical imaging and treatments.

Waves may be either transverse or longitudinal.

The ripples on a water surface are an example of a transverse wave.

Longitudinal waves show areas of compression and rarefaction. Sound waves travelling through air are longitudinal.

Students should be able to describe the difference between longitudinal and transverse waves.

Students should be able to describe evidence that, for both ripples on a water surface and sound waves in air, it is the wave and not the water or air itself that travels.

Students should be able to describe wave motion in terms of their amplitude, wavelength, frequency and period.

Students should be able to show how changes in velocity, frequency and wavelength, in transmission of sound waves from one medium to another, are inter-related.

The amplitude of a wave is the maximum displacement of a point on a wave away from its undisturbed position.

The wavelength of a wave is the distance from a point on one wave to the equivalent point on the adjacent wave.

The frequency of a wave is the number of waves passing a point each second.

Students should be able to apply T = 1/f equation which is given on the Physics equation sheet.

Students should be able to recall and apply v f λ equation.

identify amplitude and wavelength from given diagrams

describe a method to measure the speed of sound waves in air

describe a method to measure the speed of ripples on a water surface.

make observations to identify the suitability of apparatus to measure the frequency, wavelength and speed of waves in a ripple tank and waves in a solid and take appropriate measurements.

6-6 Waves – Trilogy

COMPLETE: write in the boxes below the parts of the Electromagnetic spectrum.

1.0 Figure 1 shows an incomplete electromagnetic spectrum.

Figure 1

A microwaves B C ultraviolet D gamma

1.1 Which position are X-rays found in?

Tick one box.

[1 mark]

A

B

C

D

1.2 Which three waves can cause ionisation?

Tick three boxes.

[1 mark]

Gamma rays

Infrared

Microwaves

Radio waves

Visible light

Ultraviolet

X-rays

1.3 Electromagnetic waves have many practical uses.

Draw one line from each type of electromagnetic wave to its use.

[2 marks]

Electromagnetic wave Use

Medical treatments

Radio waves

Television transmissions

Visible light

Fibre optic communications

Gamma rays

Sun tanning

COMPLETE:

Longitudinal waves

https://www.bbc.co.uk/bitesize/guides/z9bw6yc/revision/1

the vibrations are __________________ to the direction of

wave travel.

Transverse waves


the vibrations are __________________ to the direction of

wave travel.

2.0 Figure 2 shows some waves travelling along a rope.

Figure 2

2.1 Show on the diagram:

The wavelength of one of the waves (labelled with a W)

The amplitude of one of the waves (labelled with an A)

[2 marks]



2.2 State the type of waves travelling on the rope.

Explain how you can tell.

[2 marks]

Type of wave_____________________________________________

Explanation ___________________________________________________________

_____________________________________________________________________

RECALL: What is the definition for frequency?

_____________________________________________________________________

Frequency = __________________ ____ _____________________

2.3 The waves shown in the diagram were produced in two seconds.

Calculate the frequency of the waves.

[2 marks]

Frequency = ________ Hz

Period = 1 ___ _____________________

2.4 Calculate the time period of the waves.

State the unit.

[2 marks]

Time period = ________ Unit ____

3.0 Microwave ovens use microwave radiation to cook food.

The instruction manual of a microwave oven stated:

Frequency of microwaves: 10 000 million Hz.

Wavelength 0.02 m.

3.1 Calculate the speed of waves in the microwave according to the information in the instruction manual.

Give your answer in standard form.

[3 marks]

Speed = ______________ m/s

3.2 The speed of visible light is 3 x 108 m/s. Was the information in the instruction manual correct? Explain your answer.

[1 mark]

_____________________________________________________________________

_____________________________________________________________________

Which part of the electromagnetic spectrum can you see?

_____________________________________________________________________

3.3 Simon said “When the microwave is working, it lights up. That’s the microwaves.”

Explain whether Simon was correct.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

WATCH: https://www.youtube.com/watch?v=Jj2u2n_o7Cw

3.4 Putting a beaker of water in a microwave and turning it on for a minute or two will increase the temperature of the water.

Describe an experiment to investigate the relationship between the time the microwave is on and the increase in temperature of water in a beaker.

In your answer, include:

The equipment you will use

The measurements you will take

The safety precautions you will take

[6 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

https://www.youtube.com/watch?v=Jj2u2n_o7Cw



Describe the differences between Longitudinal and transverse waves

Draw and label wave diagrams of different amplitudes and wavelengths

Darry out calculations using the wave equation

Describe and interpret the ripple tank investigation (RPA)

Describe and interpret the wave on a string investigation (RPA)

Describe refraction and label ray diagrams

Describe the electromagnetic spectrum in terms of order, frequency and wavelength

Give examples of uses and risks for each part of the electromagnetic spectrum

Describe and explain the investigation on Infrared emission (RPA)

Describe and explain the investigation on Infrared absorption (RPA)



key revision

Keywords

Transverse wave Angle of incidence

Longitudinal wave Angle of reflection

Oscillation Angle of refraction

Compression Specular reflection

Rarefaction Diffuse reflection

Amplitude Gamma

Wavelength X-ray

Frequency UV

Period Visible

Absorption Infrared

Emission Microwave

Reflection Radio wave

Transmission Radiotherapy

Refraction Ionising radiation

Normal Dose

Ray Wave front

Types of wave


Features of waves Critical angle & optical fibres

Light and sound

Sound

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Keyword Definition

Transverse wave

Longitudinal wave

Oscillation

Compression

Rarefaction

Amplitude

Wavelength

Frequency

Period

Absorption

Emission

Reflection

Transmission

Refraction

Normal

Ray

Angle of incidence

Angle of reflection

Angle of refraction

Specular reflection

Diffuse reflection

Gamma

X-ray

UV

Visible

Infrared

Microwave

Radio wave

Radiotherapy

Ionising radiation

Dose

Wave front


1. Suggest how the amount of energy transferred by a wave changes as the amplitude increases.

2. When the frequency of a wave doubles, what happens to its wavelength?

3. Make a sketch of a transverse wave to explain what is meant by the terms (a) amplitude and (b) wavelength.

4. f energy is being transmitted away from the Sun, why isn’t the Sun continually cooling down?

5. Suggest what equipment you could use to measure the wavelength of a water wave, and how you should set

it up.

6. Describe what you would observe if a sound wave crossed from air into a material where it was

a) completely absorbed

b) partly absorbed and partly transmitted.

7. What are the similarities and differences between transverse and longitudinal waves?

8. Explain how waves in the electromagnetic spectrum are different from other waves.

9. What properties do all electromagnetic waves have in common?

10. Water waves are affected by the depth of the water they travel through. Do the waves travel faster in deep

or shallow water? Explain your answer.

11. Describe the similarities and differences between gamma rays and X-rays.

12. State three uses of ultraviolet radiation.

13. Suggest two advantages of using a microwave oven instead of an infrared oven.




302

The maximum displacement of a point on a wave

away from its undeisturbed position is the… Amplitude

303

The distance from a point on one wave to the

equivalent point on the next wave is the … wavelength

304

The number of waves passing a point each second is

the… Frequency

305 Name an example of a longitudinal wave Sound

306 Name an example of a transverse wave light, water, any electromagnetic

307

Oscillations are along the same direction as the

direction of travel is a _________ wave longitudinal

308

Oscillations are at right angles to the direction of

travel in a ____________ wave transverse

309

The time needed for one wave to pass a given point is

the… period

310

The region in a longitudinal wave where particles are

closest together is a … compression

311

The region in a longitudinal wave where particels are

furthest apart is a… rarefaction

312

An object is said to _________ radiation when energy

from an EM wave is taken up by the object absorb

313

An object is said to _________ radiation when a wave

can pass through the object transmit

314

The process taking place when a wave bounces off of

a surface reflection

315

The process taking place when a wave enters a

different density medium and changes direction refracion

316

Refraction changes both the _________ and

___________ of a wave direction and speed

317 Which two angles are equal in reflection angle of incidence and angle of reflection

318

Draw a transverse wave and label the wavelength and

amplidtue

319 Draw a longitudinal wave and label the wavelength

320

Write the equation linking frequency, wavelength and

wave speed v fλ

321 What is the unit of frequency? Hertz (Hz)

322 What is the unit of wavelength? metres (m)

323 What is the unit of wave speed? metres per second (m/s)

324 What is the speed of elecrtomagnetic radiation? 300 000 000 m/s

325

What is the EM radiation with the shortest

wavelength? gamma

326

What is the EM radiation with the longest

wavelength? Radio

327 What is the EM radiation with the highest frequency? Gamma

328 What is the EM radiation with the lowest frequency? Radio

329 List the EM spectrum from long to short wavelength.

Radio, microwave, infrared, visible, UV, X-rays,

gamma

330 Can EM waves travel through space? yes

331 Can sound waves travel through space? no

332 Does a sound wave travel faster in water or air? water

333 Name a use of radio waves TV and radio transmission

334 What EM wave is used for satellite communication? microwave

335 Give one use of microwaves cooking food

336 Give two uses of IR radiation electrical heaters, infrared cameras

337 Give a use of visible radiation Fibre optic communications

338 Which radiation is used in sun tanning? UV

339 Give one use of X-rays. Medical imaging

340 Give one use of gamma rays Medical treatments

341 Why are X-rays good for taking images of bone?

absorbed by bone but transmitted through soft

tissue

342 Why are gamma rays used in medical treatment? Can kill cancer cells

343 What are the risks of exposure to UV radiation? Premature skin aging, increased risk of skin cancer

344 What are the risks of exposure of X-rays?

X-rays are ionising so can cause mutations which

may result in cancer

345 What are the risks of exposure to gamma rays?

Gamma rays are ionising so can cause mutations

which may result in cancer

Science Faculty Physics 7: Magnetism Checklist

Magnetism check


Poles of a magnet

The poles of a magnet are the places where the magnetic forces are strongest. When two magnets are brought close together they exert a force on each other. Two like poles repel each other. Two unlike poles attract each other. Attraction and repulsion between two magnetic poles are examples of non-contact force.

A permanent magnet produces its own magnetic field. An induced magnet is a material that becomes a magnet when it is placed in a magnetic field. Induced magnetism always causes a force of attraction. When removed from the magnetic field an induced magnet loses most/all of its magnetism quickly.

describe the attraction and repulsion between unlike and like poles for permanent magnets

describe the difference between permanent and induced magnets.

Magnetic fields

The region around a magnet where a force acts on another magnet or on a magnetic material (iron, steel, cobalt and nickel) is called the magnetic field.

The force between a magnet and a magnetic material is always one of attraction.

The strength of the magnetic field depends on the distance from the magnet. The field is strongest at the poles of the magnet.

The direction of the magnetic field at any point is given by the direction of the force that would act on another north pole placed at that point. The direction of a magnetic field line is from the north (seeking) pole of a magnet to the south(seeking) pole of the magnet.

magnetic compass contains a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the Earth’s magnetic field.

describe how to plot the magnetic field pattern of a magnet using a compass

draw the magnetic field pattern of a bar magnet showing how strength and direction change from one point to another

explain how the behaviour of a magnetic compass is related to evidence that the core of the Earth must be magnetic

Electromagnetism

When a current flows through a conducting wire a magnetic field is produced around the wire. The strength of the magnetic field depends on the current through the wire and the distance from the wire.

Shaping a wire to form a solenoid increases the strength of the magnetic field created by a current through the wire. The magnetic field inside a solenoid is strong and uniform.

The magnetic field around a solenoid has a similar shape to that of a bar magnet. Adding an iron core increases the strength of the magnetic field of a solenoid. An electromagnet is a solenoid with an iron core.

describe how the magnetic effect of a current can be demonstrated

draw the magnetic field pattern for a straight wire carrying a current and for a solenoid (showing the direction of the field)

explain how a solenoid arrangement can increase the magnetic effect of the current.

6-7 Magnetism and electromagnetism – Trilogy

1.0 This question is about magnets.

1.1 Which statements apply to permanent magnets, which apply to electromagnets and which apply to both?

Tick the correct boxes.

[2 marks]

Permanent magnets

Electromagnets Both

Need an electric current to work

Have a constant magnetic field

Can be turned off

Have north and south poles

Often contain a coil of wire

1.2 What is an induced magnet?

Tick the correct box.

[1 mark]

A permanent magnet made by passing a current through a piece of steel

A temporary magnet made by repeatedly heating a piece of steel

A permanent magnet made by repeatedly stroking a piece of steel with a magnet

A temporary magnet made by touching a piece of steel with another magnet

WATCH: https://www.youtube.com/watch?v=DMO373nDp8M&t=58s 1.3 Describe how to find the direction of the magnetic field around a permanent magnet using a

small compass.

[3 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2.0 A student was investigating the effect of the size of current on the strength of an electromagnet.

Figure 1 shows the equipment she used.

Figure 1

2.1 Describe how the student could carry out an investigation to find the relationship between the current in the coil and the force on the iron disc.

[4 marks]

___________________________________

___________________________________

___________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

https://www.youtube.com/watch?v=DMO373nDp8M&t=58s

2.2 The student made two electromagnets, one with 100 turns of wire in the coil and one with 200 turns.

She carried out the investigation with each of the coils and plotted Graph 1.

Graph 1

The student wanted to find the ratio of the force from the two different coils at each current.

Her results are shown in Table 1.

Table 1

Current 100 coils 200 coils ratio

1.0 0.02 0.07 1 : 3.50

2.0 0.08 0.28 1 : 3.50

3.0 0.16 0.68 1 : 4.25

4.0 0.30 1.28 1 : 4.27

5.0

Complete the last row on Table 1.

2.3 The student wrote the following conclusion:

The relationship between the current and the ratio of the force from the two coils is directly proportional.

Was the student correct?

Explain your answer.

[2 marks]

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________



Describe and draw the magnetic field around a bar magnet

Draw diagrams showing attraction and repulsion of magnets

Use the right hand thumb rule

Describe how to make an electromagnet

Give examples of how electromagnets are used

Use Fleming’s left hand rule (HT only)

Calculate the size of force (HT only)

Explain how a DC motor works (HT only)



key revision

Keywords

Magnetic field Electromagnet

Magnetic material Current

Permanent magnet Motor effect

Induced magnet Magnetic flux density

Pole Split-ring commutator

Solenoid


Magnets

Electromagnets and motors

Dynamos and Transformers

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1. Suggest how you know whether an object is a magnet when you bring another magnet close to it.

2. Explain why the north pole of a compass is often called the north-seeking pole.

3. A wire goes into the plane of a page. Draw a diagram to show the magnetic field and its direction around the

wire.

Keyword Definition

Magnetic field

Induced magnet

Permanent magnet

Magnetic material

Pole

Solenoid

Electromagnet

Current

Grade 5 Questions

1 Magnetic field patterns

a) Sketch the magnetic field around a bar magnet.

b) What is a neutral point?

_________________________________________________

c) Sketch the magnetic field around the two bar magnets shown below. Mark any neutral points with an ‘X’.

d) Sketch the magnetic field pattern around a straight wire carrying a current as shown below.

2) Adding magnetic fields

The diagram shows a wire carrying a current between two magnetic poles.

a) Sketch the magnetic field due to the current in the wire, when viewed from above.

b) Sketch the magnetic field due to the magnetic poles, when viewed from above.

c) Sketch the resultant magnetic field due to the current in the wire and the magnetic poles.

d) Write ‘strong’ where the magnetic field is strongest. e) Write ‘weak’ where the magnetic field is weakest. f) This unbalanced magnetic field results in a bigger force on the ‘strong’ side of the wire. Indicate by an

arrow on the diagram the direction in which the wire moves.




346

The places on a magnet where the magnetic forces are the

strongest are called the… poles

347 What is the definition of a magnetic field?

The area around a magnet where a force acts on

another magnet or magnetic material

348

The area around a magnet where a force acts on another

magnet or magnetic material in the… Magnetic field

349 Two like poles always ______ repel

350 Tow opposite poles always _______ attract

351 What is a permanent magnet? A magnet that produces its own magnetic field.

352 What is an induced magnet?

A magnetic material which becomes a magnet when

placed in a magnetic field.

353

A magnetic material which becomes a magnet when

placed in a magnetic field is a _______ _________ induced magnet

354

What type of magnet loses its magnetism when it is

removed from a magnetic field? induced magnet

355 Which three elements are magnetic? iron, cobalt and nickel

356 Draw the magnetic field around a bar magnet teacher to draw on board…

357 Give the name for the magnet created using a coil of wire solenoid

358

Where is the strongest field in an electromganet created

by a coil of wire? inside the coil

359

What two words describe the magnetic field within the coil

of a solenoid? strong and uniform

360 What is an electromagnet?

A solenoid containing an iron core which increases its

strength

361

What is an important property of a

solenoid/electromagnet as a magnet can be switched on and off with electric current

367 Give three ways of increasing the force of a solenoid.

Add iron core, increase number of coils of wire,

increase current, move magnetic material closer

370

What two methods can you use to obesrve the field

around a bar magnet? Iron filings or plotting compass

371

Draw the magnetic field between two like poles and two

non-like poles.

373 The right hand thumb rule shows relative direction of… current and magnetic field around a wire

EXAM ANSWERS

MARK SCHEME – 1. Energy

Qu No. Extra Information Marks

1.1 Gravitational potential 1

1.2 Kinetic 1

1.3 50 × 9.8 × 2 – Gravitational potential

½ × 50 × 6.2 × 6.2 – Kinetic Both required for the mark 1

1.4 Energy lost to the surroundings

Named example (eg air gained internal energy)

Accept heat / air got warmer / sound

1

1


2.1 Coal C

Natural gas B

Nuclear power E

Oil D

Renewable fuels A

2 marks for all four correct

1 mark for 2 correct 2

2.2

Level 3 Clear, coherently organised answer.

Clear understanding of the overall energy needs of the country.

Understands the need for a range of resources.

Discusses both renewable and non-renewable energy resources, making clear points about each.

5– 6

Level 2 Some structure to answer.

Some discussion of the overall energy needs of the country.

Discusses a range of resources, giving advantages and disadvantages, although these may not be coherently linked.

3– 4

Level 1 Limited structure to answer.

Some discussion of a number of resources with limited link to the overall energy needs of the country.

1– 2

Level 0 No relevant content. 0

Indicative content

Same or greater overall energy required and/or efficiency savings mean potentially less energy required.

• Fossil fuels plentiful in supply.

• Fossil fuels contribute to global warming.

• Unlikely to be time to set up new nuclear fuel plants.

• Renewable energy resources expensive to set up.

• Renewable energy resources can be inefficient.

• Wave, hydro and/or wind likely to be useful for the UK.

• Solar power less likely to be useful.

• Biomass has negatives in land use and fertilisers etc.

Ignore discussion of nuclear waste etc.


3.1 Length = 20cm

Extension = 10cm Both required for the mark 1

3.2 0.5 × 25 × (15×10-3 )2

0.0028125

2.81×10-3 (J)

If extension of 15 used, do not allow first mark. ECF allowed:

2812.5

2.81×103 (J)

1

1

1

3.3 Either:

Attempt to use value from 3.2:

Rearrange k = Epe/(0.5 × e2)

Substitute k = (2 × 2.81×10-3)

(0.5 × (15×10-3/2)2

k = 200 N/m

Or:

Algebraic manipulation:

Rearrange k = Epe/(0.5 × e2)

Substitute multiple values

k = 2Epe/(0.5 × (e/2)2)

Cancel and compare with original

knew = 8kold

= 200 N/m

Allow 199 N/m

Allow ECF

Allow rounding errors

1

1

1

(1)

(1)

(1)


4.1 29 J of energy wasted (from light bulb, heating the air)

OWTTE 1

4.2 Heating offices saves 13 J of energy

New powerlines save 2.5 J of energy

LED bulbs save 29.7 J of energy

So replace lightbulbs

Allow ECF for incorrect bulb wastage in 4.1

All three calculations for 1 mark

1

1

4.3 Use of:

1 / 30 = 0.034

(So not correct)

Allow ECF for incorrect bulb wastage in 4.1

No mark for conclusion.

1

1

4.4 12 × 0.8 = 9.6

Time = energy / power

300 / 9.6 = 31.25 s

Allow 0 or 1 dp

1

1

1


5.1

Level 3 Clear, coherently organised answer.

Method complete with clear understanding of the experimental requirements and how the data would be analysed.

5-6

Level 2 Some structure to answer.

Main steps in method covered, with some errors or omissions.

Limited expression of data analysis.

3-4

Level 1 Limited structure to answer.

Some steps described, with little or no control variables. No data analysis. 1-2

Level 0 No relevant content. 0

Indicative content

• Heat a known mass of water.

• To a known temperature.

• Transfer the water to a beaker lagged with the first material.

• Cover the beaker with a lid of the same material.

• Record the temperature and start a clock.

• Record the temperature drop after a fixed time.

• Repeat using the same mass of water with the other materials.

• Determine which material has the smallest temperature drop in a given time/longest time for a given temperature drop.

• This will be the most effective material.


6.1 Energy supplied = power × time

= 300 × 8 × 60

= 144 × 103 J

Temperature rise = 70°C

Mass = 0.45 kg

Specific heat capacity = E/(m.)

= 144 × 103/(0.45 × 70)

= 4.6 × 103 J/kg °C

1

1

1

6.2 Any two from:

• Loss of heat to surroundings

• Heat absorbed by the beaker

• Evaporation

• Inaccurate thermometer/clock/balance

2

MARK SCHEME – 2. Electricity


1.1 50 Hz 1

1.2 230 V 1

1.3 Live wire carries the (alternating) potential difference/voltage (from the supply)

Neutral wire completes the circuit

1

1

1.4 connection is made to earth

charge can flow through the body.

or

large potential difference across the body

Accept answer in terms of a complete circuit or establishing a path (for charge to flow)

1

1

1.5 P = (3)2 x 100

900 (W)

Allow one mark for P=I2V if substitution incorrect.

Allow 900 (W) with no working for 2 marks

1

1


2.1 battery, lamp and ammeter connected in series with variable resistor

voltmeter in parallel with (filament) lamp

1

1

2.2

Level 2: A detailed and coherent description of the experiment. The response provides a logical sequence.

3-4

Level 1: Simple description of the experiment with some steps missing. The response may not be in a logical sequence and may not lead to the collection of valid results.

1-2

Level 0: No relevant content. 0

Indicative content

• ammeter used to measure current

• voltmeter used to measure potential difference

• resistance of variable resistor altered to change current in circuit or change potential difference (across filament lamp)

• resistance (of filament lamp) calculated or R=V / I statement resistance calculated for a large enough range of different currents that would allow a valid conclusion about the relationship to be made


3.1 V = 0.025 × 75

1.9 (V)

Allow 1.9 (V) with no working for 2 marks

1

1

3.2 total resistance = 6 / 0.025

R = 240 - 225

= 15 (Ω)

1

1

1

3.3 resistance decreases

current increases

1

1


4.1

battery in series with bulb and ammeter

voltmeter in parallel with the bulb

variable resistor

or

variable power supply

1

1

1

4.2 correct pair of current readings at the same pd therefore current in lamp A is twice the current in lamp B so lamp A is twice as powerful and lamp B (hence is twice as bright)

eg at 10 V, IA = 0.74A and IB = 0.37A

must refer to power/rate of energy transfer

1 1

1

4.3 R = V / I lowest R = 0.6 / 0.1 R = 6 Ω Highest R = 10 / 0.74 R = 13.5 Ω

Difference = 13.5 – 6 = 7.5 Ω

allow R= 1.0 / 0.16 R = 6.25 Ω (other values may be acceptable but the values from the graph must be when V ≤ 1V and the lamp can reasonably be assumed to be ohmic)

allow 7.25 Ω if consistent

1 1

1

MARK SCHEME – 3. Atomic Structure


1.1 solid 1

1.2 liquid 1

1.3 boiling

evaporation

1

1

1.4 the average kinetic energy of the particles 1

1.5 motion is random

range of speeds

or

range of directions

1

1

1.6 ρ = 0.032 / 0.026

ρ = 1.3 (kg/m3)

allow 1.28 (kg/m3)

allow 1.3 (kg/m3) with no working for 2 marks

1

1


2.1 food

fridge

surroundings

2 marks for all three in the correct place

1 mark for 2 or 1 in the correct place

2

2.2

Level 3: A detailed and coherent description of both the arrangement and motion of the particles in the different states of matter.

5-6

Level 2: A coherent description of both the arrangement and motion of the particles in the different states of matter.

3-4

Level 1: Simple description of the arrangement and / or motion of the particles in the different states of matter.

1-2

No relevant content 0

Indicative content

Solid

Particles closely packed in a regular pattern

Particles vibrate about a fixed position

Liquid

Particles closely packed in an irregular pattern

Particles are able to move relative to each other

Gas

Particles are widely spread in no pattern

Particles move randomly and rapidly.

2.3 Air molecules in fridge will have a greater speed.

because the air is at a greater temperature so greater kinetic energy

allow 2 marks for the converse.

1

1


3.1 conclusion is not correct

because 45 / 150 = 3.3

3.3 is less than 5

allow 40-50 for Tin

1

1

3.2 E = 1.023 x 450 x 10

E = 4 600 (J)

Answer to 2 sig. figs.

allow 2 marks for a correct answer to an incorrect number of sig figs

eg 4 604 (J)

allow 1 mark for an incorrect answer to an incorrect number of sig figs eg 4 603 (J) if substitution is correct

1

1

1

3.3 10 (minutes) 1

3.4 Correct line of best fit drawn 1

3.5 20 (°C) 1

3.6 gradient would be greater

because energy supplied per second would be greater.

so rate of increase of temperature would be greater.

or

more energy supplied (in 12 minutes)

so

greater final temperature (so greater temperature difference)

1

1

1

MARK SCHEME – 4. Atomic Structure


1.1

all three labels correct

allow 1 mark for 1 or 2 correct labels

2

1.2 has no electrons allow alpha has a positive(charge)

allow a helium (atom) has no (charge)

1

1.3 4

2

1

1

1.4 19.6 - 11.6

8 (hours)

allow ± 0.2 for each reading

allow ± 0.4 if consistent with values read from the graph

1

1

1.5 15.2 (hours) allow ± 0.2 1


2.1

allow 1 mark for each correct line

if more than one line is drawn from any type of radiation box then all of those lines are wrong

3

2.2 gamma

alpha

gamma

gamma and neutron

both required for 1 mark

1

1

1

1


3.1

Level 3 A detailed and coherent comparison of the arrangement of the particles in the different models.

5-6

Level 2: A detailed and coherent description of the arrangement of the particles in the different models.

3-4

Level 1: A simple description of the arrangement and /or a simple comparison of the arrangement of the particles in the different models.

1-2


Indicative content

nuclear model mass is concentrated at the centre / nucleus

plum pudding model mass is evenly distributed

nuclear model positive charge occupies only a small part of the atom

plum pudding model positive charge spread throughout the atom

nuclear model electrons orbit some distance from the centre / nucleus

plum pudding electrons embedded in the (mass) of positive (charge)

nuclear model the atom mainly empty space

plum pudding model is a ‘solid’ mass


4.1 (same) number of protons 1

4.2 beta

atomic / proton number increases (by 1)

or

number of neutrons decreases / changes by 1

1

1

4.3 time taken for number of radioactive nuclei to halve

or

(average) time taken for count-rate / activity to halve

1

4.4 1 half-life = 2.6 days

number of days = 7.8 days

1

1

4.5 Number of half-lives = 13/2.6

fraction = (½ x ½ x ½ x ½ x ½)

or (½)5

100 000 / 32

3125

safe

number is comparatively low, so low activity

unlikely to be substantial risk of contamination / irradiation.

or

unsafe

There are still some atoms of molybdenum left so some radiation emitted

therefore still a small risk.

no mark for safe / unsafe

1

1

1

1

1

1

MARK SCHEME – 5. Forces


1.1

Allow ticks in Thinking distance and Braking distance instead of both.

All five ticks correct: 2 marks

3 or 4 ticks correct: 1 mark

2

1.2 A and C

C and D

B and C

D and F

Both points required for each mark. 1

1

1

1

1.3

1 mark for Speed

1 mark for Velocity

2

1.4 Horizontal line above the x axis

Line drops to x axis

Line continues along x axis

Allow curved or straight line.

Do not allow vertical line

1

1

1


2.1 To allow for size of spring / to measure extension of the spring

1

2.2 Random error 1

2.3 Easier to read the scale / smaller parallax 1

2.4

Level 2: A detailed and coherent description of how to measure the spring constant. Answer includes multiple measurements and uses the gradient of a graph.

3-4

Level 1: A simple description of how to measure the spring constant. Likely to only include one reading and make reference to F = kx.

1-2


Indicative content

Change weight on spring

Measure extension for each weight

Reference to table of results

Plot graph of extension (y-axis) against weight (x-axis) (or vice versa)

Gradient is 1 / spring constant (or gradient is spring constant if axes swapped)

Reference to F = kx / Hooke’s law

2.5

𝑥 = √𝐸

0.5 𝑘

= √1.95

7.8

= 0.5 m / 50 cm

Allow 2 marks for an answer of 0.25 m / 25cm (student has forgotten to square root)

Award 2 marks for 50 cm

Award 2 marks for correct answer to more than 2 significant figures.

1

1

1


3.1 Newton’s third law

Jetpack forces the water down

So water exerts an equal (magnitude) and opposite (direction) force on the jetpack (so it moves up)

1

1

1

3.2 Combined weight = 84 × 9.8 = 820 N

Resultant force = 1900 – 820 = 1100 N

Acceleration = F/m = 1100 / 84

= 13 m/s2

v2 = u2 + 2as = 0 + 2 x 13 x 5 = 130

v = 11 m/s

1

1

1

1

1

1

MARK SCHEME – 6. Waves


1.1 D 1

1.2 Gamma rays

Ultra violet

X-rays

All three required for the mark 1

1.3 Radio waves – Television transmissions

Visible light – Fibre optic communications

Gamma rays – Medical treatments

All three correct – 2 marks

Two correct – 1 mark

If more than one line from any wave, deduct a mark, minimum of zero marks.

2


2.1 W Horizontal distance labelled between two identical points on adjacent waves

A Vertical distance from peak or trough to mean

1

1

2.2 Transverse waves

Wave moving up and down while moving from left to right

1

1

2.3 4 waves / 2 seconds

= 2 (Hz)

1

1

2.4 0.5

s / seconds

Allow ecf rom 2.3 if T = 1/f clearly used 1

1


3.1 V = f λ = 10 000 000 000 x 0.02

= 200 000 000

= 2 × 108 m/s

If wrong number of zeros used in calculation, allow ecf.

1

1

1

3.2 (No) as all electromagnetic waves have the same speed.

Ignore reference to speed changing in air.

1

3.3 (No) as the eye cannot see microwaves

The light is visible light (from a bulb)

1

1

3.4

Level 3: A detailed and coherent description of how to carry out a safe investigation including clear description of equipment to use and explanation of the measurements to take.

5-6

Level 2: A detailed and coherent description which may be lacking in some details or includes elements which are unlikely to work well (for example lengths of time over 5 mins).

3-4

Level 1: A description of an experiment which is lacking in detail or is inherently unsafe. 1-2

No relevant content

Indicative content

Equipment used (does not need to be in a list):

- Beaker

- Measuring cylinder

- Water

- Thermometer

- Stop watch / use of microwave to time

- Microwave

Investigation

- Pour ~200ml cold water into a beaker

- Measure temperature

- Put in microwave for 30 seconds

- Stir then measure the temperature after

- Repeat for a range of times up to 3 mins

- Plot a graph of the results


4.1 (for both fibres) increasing the wavelength of light decreases and then increases the percentage / amount of light transmitted

(for both fibres) the minimum transmission happens at 5 (x 10-7 metres)

the shorter fibre transmits a greater percentage of light (at the same wavelength)

1

1

1

4.2 f = c / λ

= 6 x 1014 Hz

1

1

4.3 Light refracts at boundary between cladding and core

Light changes speed / slows down in cladding

1

1

MARK SCHEME – 7. Electromagnetism


1.1 Need an electric current to work

Electromagnets

Have a constant magnetic field

Permanent magnets

Can be turned off Electromagnets

Have north and south poles

Both

Often contain a coil of wire

Electromagnets

All rows correct: 2 marks

3 or 4 rows correct: 1 mark

2

1.2 A temporary magnet made by touching a piece of steel with another magnet

1

1.3 Place compass at different points around the compass

Indication of how to draw eg note down the direction of the compass at each point around the magnet / compass points along field lines

Join each individual direction to form field lines

Accept clearly labelled diagram for any or all points

1

1

1


2.1

Level 2: A clear, coherent description of a safe experiment with given values of current (eg 0.5, 1.0, etc up to a maximum of about 5 A) and details of repeats. Includes letting the equipment cool down between experiments.

3-4

Level 1: A description of an experiment that would allow valid results to be obtained. May include currents higher than 5 A or omit details of number of readings to be taken or repeat measurements.

1-2

Indicative content

Set current to small value

Measure force on the iron disc

Repeat at regular increases of current

Repeat at least 2 more times

Allow equipment to cool between measurements

2.2 0.48 and 2.18

4.54

Allow +/- 0.2 for each reading

Allow ecf from marking point 1

1

1

2.3 (No)

The ratio increases with increased current

But as not in a linear fashion / example given

1

1


3.1 Magnetic field

Current

Force

Correct order only 1

1

1

3.2 Down onto the balance 1

3.3 From the front of the balance to the back of the balance

1

3.4 Reading would increase

As the magnetic flux density would increase

1

1


4.1 Arrow showing anticlockwise movement of the current

1

4.2 Direction: Change direction of current

Speed: Change amount of current

1

1

4.3 F = BIL = 3 ×10–2 × 0.5 × 0.04

= 6 × 10–4 (N)

1

1


5.1 To step up voltage (across the cables) /decrease the current (through the cables)

Reduces thermal energy transfer / Increases efficiency (in the cables)

Then step down voltage (across the cables) / increase the current (through the cables) (near users)

1

1

1

5.2 One of:

Politician is correct that magnetic field from underground cable drops off in short distance

Or

But it starts higher

No link to safety in the graph / no health effects

1

1

5.3 Slope = (5.4-6.0)/20

=-0.03 (/m)

Allow 0.03 for 1 mark

1

1

Documents

Physics Combined Science Revision Pack FOUNDATION Date