Chapter 1: Introduction to Physics

1.1 Understanding Physics [……/13 x 100 = ………..] explain what physics is recognize the physics in everyday objects and natural phenomena

1. A phenomenon is an ……………… that can be perceived by our…………….

2. In physics, we study …………………. ……………………, such as the eruption of volcano, rain fall, formation of rainbow and the ………………. of matter, such as length, temperature and volume.

3. There are many fields of study in physics, including ………., ………….., ……, ……….., ………, ………………, ……………….,

…………………….. and ………………. ………………….

1.2 Understanding Base Quantities and Derived Quantities [……/70x100=………..] explain what base quantities and derived quantities are list base quantities and their units list some derived quantities and their units. express quantities using prefixes. express quantities using scientific notation express derived quantities as well as their units in terms of base quantities and base units. solve problems involving conversion of units

1. A physical quantity is a ………………… ………………..that can be………………

2. Base quantities are ……………. ………………. that cannot be defined in terms of other …….. ……………..

There are ……… base quantities:………….., …………., …………., ……………… and …………………..

Physical Quantity Base S.I. UnitBase Quantity Quantity Symbol S.I. Unit Unit symbol

Length …etre

Mass …ilo…ram

Time …econd

Electric Current …mpere

Temperature …elvin

Table 1

3. Derived quantities are…………. ……………. consisting of combinations

of ………… ……………..., by …………………, ………………, or both operations.

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4. Derived quantities as well as their units are expressed in terms of base quantities and S.I. units as follows:

Given that l : length, m : mass, t : time, I : electric current, T : temperature. Derived quantities

(symbol)Expressed in base quantities Derived units

Area(A)

Volume(V)

Density( ρ )

Speed(v)

Work or Energy(W or E)

Power(P)

Velocity(v) v = Unit v =

= (read as metre per second)

Acceleration(a) a =

u = initial velocityv = final velocityt = time taken

Unit a =

= (read as metre per second per second)

Force(F)

F = mam = massa = acceleration

Unit F = kg x = kg = N (read as newton)

Impulse(Ft)

Ft = change of momentum = mv – mum = massu = initial velocityv = final velocity

Unit Ft = kg x = kg = N s(read as newton second)

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Momentum(p)

p = mvm = mass v = velocity

Unit p = kg x = kg = N s (read as newton second)

Pressure(P) P =

F = forceA = area

Unit P =

= = Pa (read as pascal)

Specific heat capacity

(c)

c =

Q = heat energym = mass

= change in temperature

Unit c =

=

=

= (read as joule per kilogram per kelvin)

Frequency(f) f =

T = period of swing; unit: second (s)

Unit f =

= = Hz (read as hertz)

Electrical charges(Q)

Q = I = electric currentt = time

Unit Q = A s = C (read as coulomb)

Resistance(R) R =

V = voltage; unit: volt (V)I = electric current

Unit R =

= = (read as ohm)

Table 2

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5. Prefixes are used to express some physical quantities that are either very big or very small.

Prefix Symbol Value

Tera

Giga

Mega

kilo

deci

centi

mili

micro

nano

pico

Table 3

6. Standard form or scientific notation: A x 10n where 1 A 10, n is an integer (integer positive or negative)

Physical Quantity ValueStandard form or Scientific

notation

Mass of earth 6 020 000 000 000 000 000 000 000 kg

Diameter of an oil molecule

0. 000 000 000 74 m

Speed or light in the vacuum

299 792 458 m s-1

Radius of earth 6 370 000 m

Mass of hydrogen atom 0. 000 021 kg

Time of a day 86 400 s

Temperature of the centre of the earth

6 000 000 K

Size of a flu virus 0.000 000 2 m

Table 4

1.3 Understanding Scalar and Vector Quantities [……./34x100 = ……..]

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define scalar and vector quantities give examples of scalar and vector quantities.

1. Scalar quantities are quantities that have ………………. but no ……………..

2. Vector quantities are quantities that have both ………………… and ………………….

Scalar Quantities Vector Quantities

3. Example :Distance(s) Displacement(s)

Total ………. of

the……………………….

Distance between …….. …………… measured along a specific direction

………….. quantity ………….. quantity

Speed Velocity

Rate of ……………

of ………………….

Rate of …………

of …………………..

Speed = Velocity =

…………… quantity …………………. quantity

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4. Annie the ant is traveling down the road to buy an umbrella for these rainy days. She walks from her nest, A to B, B to C in 10 minutes’ time as shown in the picture below:(a) What is the distance she traveled?(b) What is her displacement from A?(c) What is her speed?(d) What is her velocity?

Solution:

(a) Distance traveled =

=

= …………….

(b) Displacement of the object from A = 5 m towards the direction of AC

tan =

=

= ………….

The displacement of the ant is ………….. in the direction of ……………… from …...

(c) Speed =

=

(d) Velocity =

=………………………… towards the direction of ………..

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A

BC

4 m

3 m

Annie the ant U

1.4 Measuring Instruments [……/89x100=…..]

Measure physical quantities using appropriate instruments Explain accuracy and consistency Explain sensitivity Explain types of experimental error Use appropriate techniques to reduce errors

Accuracy, Consistency and Sensitivity in measurement & Errors

Definitions:

1. Consistency in measurements refers to ……… …………….. …………. there is among the

measurements made when a quantity is measured ……………… …………………..

2. Accuracy of a measurement is …………… …………….. the measurement made is to the

…………….. ………………… of the quantity.

3. Sensitivity of an instrument is its …………. to detect a ………… …………… in the quantity to be

measured in a ……….. ………….. of ……….

4. Figure 1.4.1 shows the result for four shooters A, B, C and D in a tournament. Every shooter shot five times.

:

Figure 1 Table 1

5. Error is ……………. caused by measuring ……………… or the …………….. or the …………. ……………. of the surroundings.

6. Two main types of errors : ………………. …………. and ………………… ………….

Table 2

Shooter Consistency AccuracyA

B

C

D

Systematic Error Random Error Caused by:

i. Error in instrumentsii. Error in calibration

Caused by:i. Surroundings factors, such as

temperature and windii. Carelessness of the observer

Examplei. ……………….

Examplei. …………………..ii. Error in ……………….

………….. be reduced or overcome …………. be reduced Way of correction

i. Take the error into account Ways of correction

i. Take several readings and calculate the average value.

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Parallax errorsDefinition:A parallax error is an………… in reading an instrument because the observer’s eyes and pointer are not

………………………………………….. to the plane of the scale.

Concept & Explanation:1. Figure 2, 3 and 4 show the correct positioning of the observer’s eyes to avoid parallax errors.

2. How to avoid parallax error?

(a) position of eyes must be………………………………………with the scale of the reading to be taken.

(b) When taking reading from an ammeter, we must make sure that the eyes are exactly

in front of the pointer, so that the………………… of the pointer in the mirror is …………….

…………………. the pointer. In other words, the reflection of the pointer on the mirror could not

be seen by the observer, then it is free from………………… ……………..

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Measuring Instruments & AccuracyMeasuring Instruments:

Table 3(A) Instruments measuring length 1. Metre Rule

Figure 52. Vernier Calipers

The same wire is measured by a vernier caliper. The reading is as follows:

Figure 6

3. Micrometer Screw GaugeThe diameter of the wire is measured by a micrometer screw gauge. The reading is as follows:

Figure 7

Physical Quantity Measuring Instruments

Length

Current

Mass

Temperature

Time

Voltage

Ruler A Ruler BSensitivityAccuracyLength of wire

SensitivityAccuracyLength of wire

Sensitivity AccuracyDiameter of wire

9

4 5

0 5 10

20

250 5

wire

2 3 4 510Ruler A

2 3 4 50 1 Ruler B

Vernier Calipers

Positive zero error Negative zero error

Figure 9 Positive zero error = + 0.08 cmAll measurements taken with this vernier calipers must be corrected by subtracting 0.08 cm from the readings.

Figure 10Negative zero error = - ( 0.1 – 0.08 ) cm = - 0.02 cmAll measurements taken with this vernier calipers must be corrected by subtracting - 0.08 cm, which is adding 0.08 cm to the readings

Eample

(i) Figure 11 (ii) Zero error = + 0.04 cmVernier caliper reading = 0.4 + 0.01 = 0.41 cmCorrected reading = vernier caliper reading – zero error= 0.41 – 0.04= 0.37 cm

Example

(i) Figure 12 (ii) Zero error = -(0.1 – 0.07) cm = - 0.03 cmVernier caliper reading = 3.6 + 0.02 = 3.62 cmCorrected reading = vernier caliper reading – zero error= 3.62 – (-0.03)= 3.62 + 0.03= 3.65 cm

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1) How to read from a vernier caliper?

Figure 8 shows the use of a vernier caliper to measure the size of the inner diameter of a beaker.Inner diameter= main scale reading + vernier scale reading = 3.2 + 0.04= 3.24 cmFigure 8

Exercise:1 Write down the readings shown by the following

(a)

(b)

(c)

(d)

2. (a) The following diagram shows the scale of a vernier calliper when the jaws are closed.

Zero error = …………

(b) The following diagram shows the scale of the same vernier calliper when there are 40 pieces of cardboard between the jaws.

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0 5 10

0 1

0 5 10

6 7

0 5 10

7 8

0 5 10

5 6

0 5 10

0 1

Answer: ……………..

Answer: ……………..

Answer: ……………..

Answer: ……………..

Reading shown = ……………………

Corrected reading = ……………………… = ……………………………

0 5 10

4 5 A B

Q P

Micrometer Screw Gauge1. How to read from a micrometer screw gauge?

Figure 13Figure 13 shows the use of a micrometer screw gauge to measure the size of a spherical object.Main scale reading = 5.5 mmThimble scale reading = 12 x 0.01

= 0.12 mmFinal reading = 5.5 + 0.12

= 5.62 mm

2. Positive zero error and negative zero error

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Positive zero error Negative zero error

Figure 14 Positive zero error = + 0.04 mmAll measurements taken with this micrometer screw gauge must be corrected by subtracting 0.04 mm from the readings

Figure 15

Negative zero error = - 0.04 mmAll measurements taken with this micrometer screw gauge must be corrected by subtracting - 0.04 mm, which is adding 0.04 mm from the readings

Example

Figure 16Zero error = + 0.01 mmmicrometer screw gauge reading= 2.5 + 0.35= 2.85 mmCorrected reading = micrometer screw gauge reading – zero error= 2.85 – 0.01= 2.84 mm

Example

Figure 17 Zero error = - 0.03 mmmicrometer screw gauge reading = 6.0 + 0.08= 6.08 mmCorrected reading = micrometer screw gauge reading – zero error= 6.08 – (-0.03)= 6.08 + 0.03= 6.11 mm

Exercise:

1. Write down the readings shown by the following micrometer screw gauges.

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(a) (b)

Answer: …………………………. Answer:…………………..(c) (d)

Answer:………………………… Answer:…………………….

2. (a) Determine the readings of the following micrometer screw gauges.

Zero error = ……….. mm Zero error = …......….. mm

(b) Determine the readings of the following micrometer screw gauges.

(B) Instrument Measuring Current : Ammeter

14

25

300 5

40

5 10 15 45

0 0

45

5

0

0

5

0

0 0 5

15

20

30

350 5

Zero error = ………… Reading shown = …………………..=……………………

Corrected reading =………………..= ……………….

5

100

Ammeter ranged …………………….Sensitivity =……………….Accuracy =……………….

Figure 18

Doubled ranged ammeterUpper scale ranged ………………………Sensitivity =……………; accuracy =……………..Lower scale ranged…………………………Sensitivity =…………… accuracy =………………Reading =…………………..

Figure 19

Miliammeter…………………………..

Sensitivity =………………

Accuracy = ………………Reading =………………..

Figure 20

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(C) Instrument Measuring Temperature :Thermometer

Figure 21

Accuracy = …………..

(D) Instrument Measuring Time

Mechanical StopwatchAccuracy =…………..

Reading =……………

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Digital StopwatchAccuracy =………………Reading = ………………..

Figure 22: Mechanical stopwatch

Figure 23: Digital stopwatch

1.5 Scientific Investigation […../24x100=…….] Identify variables in a given situation Identify a question suitable for scientific investigation Form a hypothesis Design and carry out a simple experiment to test the hypothesis Record and present data in a suitable form Interpret data to draw a conclusion Write a report of the investigation

Clone of SPM Trial Exam of the Perak State year 2003: Paper 3 / Section B/ Question 2Notes: MV -manipulated variable; RV-responding variable; C- constant

Two twin brothers, Micheal and Jackson, of the same size, are swinging happily on the swings at a playground as shown in the figure above.

However, the ropes that is holding the swing where Micheal is sitting is longer than Jackson’s. And, Micheal notices that his swing is swinging slower than his brother, Jackson. Using this information;(a) make a suitable inference, [1 mark](b) state one appropriate hypothesis that could be investigated, [1 mark](c) describe how you would design an experiment to test your hypothesis using a bob, strings and other

apparatus.In your description, state clearly the following:(i) aim of the experiment(ii) variables in the experiment(iii) list of apparatus and materials(iv) arrangement of the apparatus(v) the procedure of the experiment, which includes the method of controlling the manipulated

variable and the method of measuring the responding variable.(vi) the way you would tabulate the data(vii) the way you would analyze the data [10 marks]

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Keywords to indicate the must-use-apparatus and hinting on the Pendulum experiment

Keywords to indicate C is mass

Keywords to indicate MV is length

Keywords to indicate RV is time of making a complete swing

Answer: (a) Inference: …………………. influences ………………………………….(b) Hypothesis: When the ………………… increases, the …………………………… increases.(c)Marks1st mark Aim

To investigate the relationship between …………………..

and ……………………….2nd mark MV: RV:

3rd mark C

4th mark List of apparatus & materials

………………, ............., bob, string, retort stand and clamp, split cork.

5th mark Arrangement of apparatus

6th mark Method to control MV Measure …………………… by using a …………………..

(Notes: Active or passive sentences are acceptable. Must have a value + measuring instrument )

7th mark Method to control RV Measure ………………………….. by using a……………………

Calculate period of a swing, T as follows: ………………..

8th mark Repetition : Repeat the experiment with l = ………………………..using the same ………………

9th mark : Tabulate data 10th mark : Analyze data Plot graph ………..against ……………

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………….

……………