J Gravity and space Unit guide - Physicslocker Index · 2013-09-16 · unit 7K Forces and their effects and unit 7L The Solar System and beyond. ... J Gravity and space Unit guide

This unit builds on:unit 7K Forces and their effects and unit 7L The Solar System and beyond. The historical impact ofdiscoveries in astronomy is covered in unit 21 Scientific discoveries in the history scheme of work.

Sheet 1 of 1© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

J Unit guideGravity and space

Where this unit fits in Prior learning

The concepts in this unit are: gravity causes an attractive force between any two objects with mass; gravitational attraction depends onthe mass and the objects and their distance apart; gravitational attraction keeps the Solar Systemtogether; ideas about the Solar System have changed over time.

This unit leads onto:further work in key stage 4 on theories about the nature and evolution of the Universe.

This unit relates to:unit 9K Speeding up.

To make good progress, pupils startingthis unit need to understand:• that the gravitational attraction of the

Earth on a mass causes weight• about the planets of the Solar System,

how they orbit the Sun, and howsatellites, e.g. moons, orbit them

• that forces affect the motion of bodies.

Framework yearly teaching objectives – Forces• Recognise that gravity is a force of attraction between objects, that this force is greater for large objects like the Earth but gets less the further

an object moves away from the Earth’s surface; use these ideas to explain:– how weight is different on different planets;– how stars, planets, and natural and artificial satellites are kept in position in relation to one another.

• Be able to give examples of the uses of artificial satellites.

Expectations from the QCA Scheme of Work At the end of this unit …

… most pupils will … … some pupils will not have made so muchprogress and will …

… some pupils will have progressed furtherand will …

in terms of scientific enquiry NC Programme of Study Sc1 1a, c; 2i, j, m

• use a model of gravitational attraction toexplain orbiting

• describe how ideas of the nature of the SolarSystem have changed over time and relatethese to available evidence

• make effective use of secondary sources tofind information from recent space explorationabout the nature of the Solar System.

• describe some early ideas about the SolarSystem.

• explain how experimental evidence has led tochanges over time in models of the SolarSystem

• evaluate recent information and ideas aboutthe origin of the Moon.

in terms of physical processes NC Programme of Study Sc3 1b; Sc4 2b, 4c, e

• recognise that gravitational attraction is auniversal force of attraction between objectsand that this force depends on their massesand distance apart

• describe how weight is different on differentplanets

• give examples of the use of artificial satellites.

• recognise that weight is less on the Moon• describe gravitational attraction as a force

which acts throughout the Solar System• give examples of the use of artificial

satellites.

• use data to compare gravity on differentplanets

• describe how the forces on rockets orsatellites vary as they travel away from theEarth.

Suggested lesson allocation (see individual lesson planning guides)Direct route

J1A massiveproblem

J2Satellites

J3The Solar System

J4Birth of the Moon – Thinkabout theories and evidence

Booster 5Focus on forces –Forces all around

Extra lessons (not in Pupil book)

J3 The Solar SystemExtra lesson forActivity J3a.

Review and assessprogress(distributedappropriately)

MisconceptionsThat only planets/moons with an atmosphere have gravity, because weight is caused by the atmosphere pushing down.Satellites are in a region of zero gravity.

Health and safety (see activity notes to inform risk assessment)Risk assessments are required for any hazardous activity. In this unit pupils use a fast-moving object to explore orbits.

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J1Lesson planning

guideA massive problem

Suggested alternative starter activities (5–10 minutes)

Introduce the unit

Unit map for Gravity andspace.

Learning objectivesi Gravitational attraction depends on the mass of the two objects attracting each other.ii Gravitational attraction depends on the distance apart of the two objects attracting each other.iii Explain how rockets are launched from Earth into space.iv The gravitational attraction on an object decreases as it travels away from Earth. (red only)

Scientific enquiryv Select and use appropriate methods for communicating qualitative and quantitative data about gravity. (Framework YTO Sc1 9e)vi Describe patterns in data of gravity on different planets. (Framework YTO Sc1 9f)

Learning outcomes

Share learning objectives

• Recognise that thegravitational attractionbetween two objects dependson: (i) their masses and(ii) their distance apart.

• Explain how rockets arelaunched from Earth. (Sc1)

Problem solving

Show an animation of theSolar System to introducethe idea of gravity keepingthe planets in orbit.Catalyst InteractivePresentations 3

Brainstorming

Imagine taking a trip fromthe Earth to the Moon.Pupils discuss in groups theproblems likely to beencountered and ideas ofhow they may be overcome.

Capture interest

Show a video clip of arocket launch. Repeat it ata slower speed.Catalyst InteractivePresentations 3

Suggested alternative plenary activities (5–10 minutes)

Review learning

Pupils match the masses ofvarious objects to their weighton different planets, given thesurface gravities of the planets.

Sharing responses

Pupils discuss theirresponses to Activity J1a.

Group feedback

Groups of pupils discusstheir answers to ActivityJ1b and report back tothe class.

Word game

Pupils discuss word pairs(e.g. mass/weight,rocket/jet, Earth/Jupiter,Sun/star).

Looking ahead

Pupils complete diagrams to showthe forces on a rocket at variouspoints on its journey from Earthto the Moon. (red only)

Suggested alternative main activitiesActivity

Textbook J1

Activity J1a Paper

Activity J1b Paper

Activity J1c Practical

Activity J1dCatalyst InteractivePresentations 3

Learningobjectivessee above

i, ii, iii andiv

i, v and vi

i, ii, v and vi

iii and vi

ii and iv

Description

Teacher-led explanation and questioning OR Pupils work individually,in pairs or in small groups through the in-text questions and thenonto the end-of-spread questions if time allows.

Gravity on the planets Pupils answer some questions about massand weight on the Earth, Moon and planets.

Investigating gravity Pupils reinforce the concept of gravitationalattraction using a data interpretation exercise. They use informationon the Resource sheet to help them answer some questions.

Rocketing away! Pupils watch some demonstrations of rocket motionand then answer some questions.

Support animation showing the effect of gravity on a mass.

Approx. timing

20 min

15 min

20 min

25 min

10 min

Target group

C H E S

R/G G R S

✔ ✔

✔ ✔ (✔)

✔

✔

Key wordsthrust

Out-of-lesson learningHomework J1Textbook J1 end-of-spread questionsActivity J1bUse secondary sources to find out more about the nature of the Solar System

Most pupils will ...

• recognise that gravity is a universal forceof attraction between objects and thatthis force depends on their masses andtheir distance apart

• describe how weight is different ondifferent planets

• make effective use of secondary sourcesto find information about the nature ofthe Solar System.

Some pupils, making less progress will ...

• recognise that weight is less on the Moon• describe gravity as a force which acts

throughout the Solar System• recognise that gravitational attraction depends

on mass and distance• use secondary sources for investigations.

Some pupils, making more progress will ...

• use data to compare gravity on different planets• describe how the forces on rockets or satellites

vary as they travel away from the Earth.



J2Lesson planning

guideSatellites

Learning objectivesi Uses of artificial satellites.ii Keeping satellites in orbit.

Scientific enquiryiii Use a model of gravitational attraction to explain how satellites stay in orbit.


Recap last lesson

Quick questions forpupils to answer as theycome in.


• Describe some of the usesmade of artificial satellites.

• Use a model to explain howsatellites stay in orbit. (Sc1)

Problem solving

Demonstration of circularmotion – whirling an objectaround on a string.

Brainstorming

Group discussion on what asatellite needs to have towork and to send andcollect data.

Capture interest

Show photos of artificialsatellites (e.g. weather,communications, spacestations).Catalyst InteractivePresentations 3


Review learning

True/false quiz on factsabout satellites.

Sharing responses

Pupils discuss theirresponses to Activity J2a.

Group feedback

Play ‘What am I?’ game. Thewinning group is the onewith the most correct answersin the allotted time.

Word game

Invite volunteer pupils tolist as many things aspossible related to thelesson in 30 seconds.

Looking ahead

Ask the question: ‘How dowe know the Earth isround?’

Learning outcomes


• give examples of the use of artificialsatellites.


• give examples of the use of artificial satellites.


• also understand that satellites are constantlyfalling in a curve that keeps them in orbit.

Key wordsartificial satellite, natural satellite, geostationary orbit, polar orbit

Out-of-lesson learningHomework J2Textbook J2 end-of-spread questionsActivity J2aResearch uses of artificial satellites

Suggested alternative main activities

Activity

Textbook J2

Activity J2a Paper

Activity J2b Catalyst InteractivePresentations 3


i, ii and iii

i, ii and iii

i, ii and iii

Description


Escape from Earth Pupils review several different concepts first covered in Year 7 work on forces such as weight, mass andgravity that relate to the work covered in this unit.

Animation showing satellite moving tangentially to Earth with forceof gravitational attraction towards Earth all the time.

Approx.timing

20 min

20–30min

5–10 min

Target group

C H E S

R/G G R S

✔

✔ ✔ ✔



J3Lesson planning

guideThe Solar System

Learning objectivesi Learn about the two main models of the Solar System.

Scientific enquiryii Use models to understand the Solar System.iii Appreciate that these models have changed over time. (Framework YTO Sc1 9a)iv Select and use appropriate methods for communicating qualitative and quantitative data about gravity. (Framework YTO Sc1 9e)


Recap last lesson

Check progress by playingbingo to reinforce keywords.

Share learningobjectives

• Describe the two mainmodels of the SolarSystem.

• Explain which model iscorrect and use it tounderstand the SolarSystem. (Sc1)

Problem solving

Use a table of data aboutthe planets to decide whichones it might be possible tolive on.

Brainstorming

Show an OHT of planetscircling the Sun. Pupilsproduce a mnemonic to helpthem remember the order ofthe planets.

Capture interest

Show photos/video clips ofthe telescopes used throughthe ages to view theplanets, moons etc., fromGalileo’s to Hubble.Catalyst InteractivePresentations 3


Textbook J3

Activity J3a ICT

Activity J3b Paper

Activity J3cCatalyst InteractivePresentations 3


i, ii and iii

i, ii, iii and iv

i, ii and iii

i, ii and iii

Description


Famous scientists Pupils develop information handling skills andbecome familiar with the work of some of the most importantastronomers.

Earth-centred and Sun-centred models Pupils read about the twomodels of the Solar System and then answer some questions.

Animation of geocentric model with everything else moving aroundEarth on celestial spheres followed by heliocentric model with theplanets orbiting the Sun.

Approx.timing

20 min

30 min

30 min

5–10 min

Target group

C H E S

R/G G R S

✔

✔ ✔

✔ ✔ ✔


Review learning

Pupils play a ‘millionaire’quiz.

Sharing responses

Each group makes a shortpresentation to summarisetheir research in Activity J3a.

Group feedback

In groups, pupils write anargument for and againsteach of the two models of theSolar System.

Word game

Wordsearch using key wordsfrom the unit to checkprogress.

Looking back

Pupils revise andconsolidate knowledge fromthe unit.

Learning outcomes


• describe how ideas of the nature of the SolarSystem have changed over time and relatethese to available evidence.


• describe some early ideas about the SolarSystem.


• explain how experimental evidence has led tochanges over time in models of the SolarSystem.

Key wordsgeocentric, heliocentric

Out-of-lesson learningTextbook J3 end-of-spread questionsHomework J3All or part of Activity J3a could be set



J4Lesson planning

guideBirth of the Moon – Think abouttheories and evidence

Learning objectivesi Study how scientists have explained the unusual size of the Moon over the last two hundred years.The structure of this lesson is based around the CASE approach. The starter activities give concrete preparation. The main activities move away from theconcrete towards a challenging situation, where pupils need to think. The extended plenary gives pupils time to discuss what they have learnt, tonegotiate a method to commit to paper and express their ideas verbally to the rest of the class.

Scientific enquiryii Understand that scientific ideas change over time, depending on the evidence available. (Framework YTO Sc1 9a)


Bridging to the unitShow a video clip of the first Moonlanding in 1969.Catalyst Interactive Presentations 3

Setting the contextShow an OHT of scale drawings ofEarth, Jupiter and Neptune withtheir moons.

Concrete preparation (1)Pupils discuss: (i) What do wemean by a theory? (ii) Why do weneed theories?

Concrete preparation (2)Teacher-led discussion on the needfor evidence to support theoriesand models.


Textbook J4

Activity J4a ICT

Activity J4b Discussion

Activity J4cCatalyst InteractivePresentations 3


i and ii

i and ii

i and ii

i and ii

Description

Teacher-led explanation and questioning OR Pupils workindividually, in pairs or in small groups through the in-textquestions and then onto the end-of-spread questions if time allows.

Researching Moon birth Pupils use the Internet to find out moreabout one of the theories on how the Moon was formed. They thenprepare a poster/fact sheet/presentation for the rest of the class.

Acting out Moon birth Working as part of a small group, pupilsproduce a role play to illustrate one of the theories of how theMoon formed.

Animations of the main theories of how the Moon was formed.

Approx.timing

30 min

45 min (mayincludehomework)

40 min

5 min

Target group

C H E S

R/G G R S

✔

✔

✔ ✔ ✔


Group feedback

Pupils have 5–10 minutes to discuss, write down or display what they havelearned about a model, the need for evidence to support it and how the modelmay need to be modified or abandoned as further evidence is obtained.

Bridging to other topics

Ask pupils to think of other areas of science where a model hasbeen replaced as further methods of obtaining evidence aredeveloped.

Learning outcomes


• use the example of ideas about the origin ofthe Moon to follow how scientific ideaschange over time in the light of newevidence.


• use the example of ideas about the origin ofthe Moon to realise that scientific ideaschange over time in the light of new evidence.


• use the example of ideas about the origin ofthe Moon to explain how scientific ideaschange over time in the light of new evidence

• evaluate recent information and ideas aboutthe origin of the Moon.

Key wordsred only: volatile

Out-of-lesson learningTextbook J4 end-of-spread questionsFind out more about another scientific model and list the importantpoints


J Unit mapGravity and space


Copy the unit map and use these words to help you complete it.You may add words of your own too.

artificial satellitecommunicationsEarthgeocentricgeostationarygravitational attractiongravityheliocentric

kilogrammassMoonnatural satellitenewtonorbitplanet(s)polar

rocketSuntelephonetelevisiontheorythrustweatherweight

Gravity and space

Mass and weight Birth of the Moon

The Solar SystemSatellites

Unitmaps.qxd 18-Jun-04 11:36 AM Page 10


J1 StartersA massive problem

Introduce the unit� Either draw the outline of the unit map on the board then

ask pupils to give you words to add, saying where to addthem. Suggest some words yourself when necessary to keeppupils on the right track.

� Or give out the unit map and ask pupils to work in groupsdeciding how to add the listed words to the diagram. Thengo through it on the board as each group gives suggestions.

Share learning objectives� Ask pupils to write a list of FAQs they would put on a website

telling people about gravity and space. Collect suggestions asa whole-class activity, steering pupils towards those related tothe objectives. Conclude by highlighting the questions youwant them to be able to answer at the end of the lesson.

Problem solving� Pupils watch an animation of the Solar System. Ask the

class to suggest why the planets orbit the Sun, thusintroducing the idea of the attractive force of gravity.

Brainstorming� Ask pupils to imagine taking a trip from the Earth to the

Moon.

� Working in small groups, they discuss the problems likely tobe encountered and suggest how these problems may beovercome.

� One person from each group acts as spokesperson andreports back to the class.

Capture interest� Pupils watch a video clip of a rocket launch and watch it

again in slow motion.

� Ask pupils to comment on what they have seen and suggesthow the rocket is able to travel into space. If necessary, leadpupils towards the idea that the hot gases ejected backwardsprovide an equal and opposite force to propel the rocketforwards.

➔ Unit map

➔ Catalyst Interactive Presentations 3

Questions1 What shape is the orbit of a planet?

2 Why do the planets stay close to theSun instead of travelling into deepspace?

3 (Extension) Suggest why the planetsorbit the Sun rather than the Sunorbiting a planet.

Answers1 (almost) circular; 2 gravitationalattraction; 3 the mass of the Sun is muchgreater than the masses of the planets.



Introduce the unit

Unit map for Gravity andspace.


• Recognise the gravitationalattraction between twoobjects depends on (i) theirmasses and (ii) theirdistance apart.

• Explain how rockets arelaunched from Earth. (Sc1)

Problem solving

Show an animation of theSolar System to introducethe idea of gravity keepingthe planets in orbit.Catalyst InteractivePresentations 3

Brainstorming

Imagine taking a trip fromthe Earth to the Moon.Pupils discuss in groups theproblems likely to beencountered and ideas ofhow they may be overcome.

Capture interest

Show a video clip of arocket launch. Repeat it ata slower speed.Catalyst InteractivePresentations 3

J-Starters.qxd 01-Apr-04 11:10 AM Page 1


J2 StartersSatellites

Recap last lesson� Pupils answer quick questions on the last lesson shown

as an OHT as they come in.

� Discussion of answers once everyone has completed theexercise.

Share learning objectives� Write the learning objectives on the board and show why

it is important that we know about these ideas.

� Tell pupils about some of the uses of artificial satellites –communications, weather forecasting, spying, etc.

� Tell pupils how important a development it was whenhumans discovered how to put a satellite into orbit.

Problem solving� Pupils watch a demonstration of circular motion. Whirl

an object attached to a length of string in a horizontalcircle round your head.

� Pupils observe the effect of increasing the speed ofrotation.

Brainstorming� Pupils work in small groups to discuss what a satellite

needs in order to work and to send and collect data.

� A spokesperson from each group reports back to the class.

� Write the ideas on the board to summarise thediscussion.

Capture interest� Show pupils some photos of artificial satellites

(e.g. weather, communications, space stations).

� Ask pupils to suggest what they think they might beused for.

➔ Pupil sheet

Answers1 600 N; 2 240 N; 3 60 kg; 4 Neptune; 5 Mercury, Mars or Pluto

Equipmentlength of string (about 1 m); squash ball ortennis ball (the ball should be firmlyattached to the end of the string preferablyby threading the string through the ballthen knotting it)



Recap last lesson

Quick questions for pupilsto answer as they come in.

Share learningobjectives

• Describe some uses of artificial satellites.

• Use a model to explainhow satellites stay inorbit. (Sc1)

Problem solving

Demonstration of circularmotion – whirling an objectaround on a string.

Brainstorming

Group discussion on what asatellite needs to have towork and to send andcollect data.

Capture interest

Show photos of artificialsatellites (e.g. weather,communications, spacestations). Catalyst InteractivePresentations 3


J2 StartersSatellites

Recap last lesson


Planet Surface gravity in newtons per kilogram (N/kg)

Mercury 4

Venus 9

Earth 10

Mars 4

Jupiter 26

Saturn 11

Uranus 11

Neptune 12

Pluto 4

Use the table above to help you answer the questionsbelow.

1 Amy has a mass of 60 kg. What does she weigh onEarth?

2 What would she weigh on Mars?3 What would her mass be on Jupiter?4 A sled has a mass of 25 kg and weighs 300 N.

Where is it?5 Where could it be if it weighed 100 N?



J3 StartersThe Solar System

Recap last lesson� Pupils select nine words from the list to write into their

bingo grid.� Read out definitions from the teacher sheet in any

order. Pupils match these to their chosen words. Thegame is over when a pupil can strike out a line.

� The ‘winning’ pupil has to recall the definitions of thewords as they read each one in the winning line to theclass.

Share learning objectives� Write the learning objectives on the board and show

why it is important that we know about these ideas.� Tell pupils that there are two main models of the Solar

System – the geocentric model and the heliocentricmodel.

� Tell pupils that they are going to find out about the twomodels, and learn which one is thought to be correct.

� Talk about day and night, the seasons, a year, etc., andhow they can be explained by this model of the SolarSystem.

Problem solving� Pupils use a table of data about the planets to decide

which ones it might be possible to live on. (This recapsa similar activity from Year 7.)

� Ask pupils to justify their choices in a class discussion.

Brainstorming� Pupils look at an OHT of planets circling the Sun with

their names clearly marked.� Pupils produce a mnemonic to help them remember the

order of the planets.� Now ask pupils questions to test the effectiveness of the

mnemonic.

Capture interest� Pupils look at photos or video clips of the telescopes

used through the ages to view the planets, moons, etc.,from Galileo’s telescope to the Hubble telescope.

� Now ask pupils to comment on the differences betweenthe telescopes and explain the advantages of morerecent ones, such as Hubble.

➔ Pupil sheet

➔ Teacher sheet

➔ Pupil sheet

➔ Pupil sheet



Recap last lesson

Check progress by playingbingo to reinforce keywords.


• Find out about the two mainmodels of the Solar System.

• Be able to explain whichmodel is correct and use itto understand the SolarSystem. (Sc1)

Problem solving

Pupils use a table of dataabout the planets todecide which ones it mightbe possible to live on.

Brainstorming

Show an OHT of planetscircling the Sun. Pupilsproduce a mnemonic tohelp them remember theorder of the planets.

Capture interest

Show photos/video clips ofthe telescopes used throughthe ages to view theplanets, moons etc., fromGalileo’s to Hubble.Catalyst InteractivePresentations 3




Recap last lesson

Bingo!

Choose nine words from the ones below and write them in the empty grid.

Cross out each word when you hear the teacher read out its definition.Shout BINGO! when you have crossed out a line of three words on the card.The line can be across, down or diagonally.

Earth

gravity

Mars

mass

Moon

orbit

planet satellite thrust

rocket Sun weight


XX Starters

Recap last lesson

Teacher sheet

Read out the definitions below in any order.

1 The planet we live on. [Earth]

2 This keeps the planets in orbit around the Sun. [gravity]

3 The nearest planet to us. [Mars]

4 The amount of material in an object. [mass]

5 It goes around the Earth once a month. [Moon]

6 The curved path of a planet or satellite. [orbit]

7 An object that goes around the Sun. [planet]

8 This travels into space. [rocket]

9 An object that goes around another object. [satellite]

10 The star at the centre of the Solar System. [Sun]

11 The push from a rocket. [thrust]

12 The force of gravity on a mass. [weight]


J3 The Solar System



Problem solving

Look at the table of data about the planets of the Solar System.Decide which planets, if any, it might be possible to live on. Give reasons to support your answer.


Planet Diameter in Approx. distance Average Density in kilometres (km) from the Sun in temperature kilograms per

millions of in degrees cubic metre kilometres Celsius (kg/m3)

(million km) (ºC)

Mercury 5000 60 430 5500

Venus 12 000 110 470 5200

Earth 12 800 150 15 5500

Mars 7000 230 –30 4000

Jupiter 140 000 780 –150 1300

Saturn 120 000 1400 –180 700

Uranus 52 000 2900 –210 1300

Neptune 50 000 4500 –220 1700

Pluto 3000 6000 –230 500


XX Starters


J3 The Solar System

Brainstorming

Sun

MercuryJupiter

EarthPluto

Neptune

Venus

Saturn Mars Uranus



J4 StartersBirth of the Moon – Think about

Bridging to the unit� Show a video clip of the first Moon landing in 1969.

� When he first stepped onto the Moon, Neil Armstrong said, ‘One smallstep for man, one giant leap for mankind.’ Ask pupils what they thinkhe meant.

Setting the context� Pupils look at an OHT showing Earth, Jupiter and Neptune with their

moons, all drawn to a suitable scale. This will show how large Earth’sMoon is in comparison with other moons.

� Ask pupils what this suggests about the way Earth’s Moon was formed.

Concrete preparation (1)� Pupils discuss the following questions in small groups:

– What do we mean by a theory?

– Why do we need theories?

� Write the views of each group on the board and lead the pupils towardssensible answers. Comments might include:

– A theory is an idea, or model, that explains an observed effect. It maybe modified or replaced by a new theory if evidence is found thatproves it to be incorrect. A relevant example to mention is thetheories of the Solar System.

– We need theories to help us to understand effects that we cannot see(because they are too small, such as atoms) or cannot experiment ondirectly (because we cannot reach them, such as the Solar System).

Concrete preparation (2)� Lead a discussion on the need for evidence to support theories and

models. Refer to the particle model in solids, liquids and gases, askingpupils to suggest pieces of evidence that support the particle model.

➔ Catalyst InteractivePresentations 3

➔ Pupil sheet


Bridging to the unit

Show a video clip of the firstMoon landing in 1969.Catalyst Interactive Presentations 3

Setting the context

Show an OHT of scale drawings ofEarth, Jupiter and Neptune withtheir moons.

Concrete preparation (1)

Pupils discuss: (i) What do we meanby a theory? (ii) Why do we needtheories?

Concrete preparation (2)

Teacher-led discussion on the needfor evidence to support theories andmodels.


J4 StartersBirth of the Moon

Setting the context

The data in the table has been usedto draw the planets and their moonsto the scale: 1 cm = 10 000 km(0.0001 cm per km).

Earth and Moon

Jupiter and some of its moons

Neptune and its moon

Jup

iter

IoCallisto

Ganymede

Europa

Earth Moon


Planet Moon Actual Scale diameter diameter in in centimetres

kilometres (km) (cm)

Earth 12 800 1.28

Moon 3500 0.35

Jupiter 143 000 14.3

Io 3600 0.36

Europa 3100 0.31

Ganymede 5300 0.53

Callisto 4800 0.48

Neptune 49 400 4.94

Triton 2700 0.27

Neptune Triton


J1aTeacher

activity notesGravity on the planets

Running the activityPupils complete the questions on the Pupil sheets.

Core: Pupils complete a table connecting mass, weight and surface gravity on each of the planets andthen answer questions about going to the Moon.

Help: Questions are restricted to mass and weight on the Earth and the Moon.

PitfallsIt is probably worth emphasising that mass (in kilograms) is the same everywhere but weight (innewtons) varies from place to place.

ICT opportunitiesIt would be possible to set up a spreadsheet for the table in Question 1 on the Core sheet.

AnswersCore:

1

2 a 3600 N b 360 kg

3 a 240 N b 40 N

Help:

1 600 g

2 6 N

3 6 kg (or 6000 g)

4 6 kg (or 6000 g)

5 10 N

6 3600 N

7 360 kg

8 240 N

9 40 N


Type Purpose DifferentiationPaper Pupils answer some questions about mass and weight on the Earth, Moon and planets. Core, Help

Planet Surface gravity Weight in Mass inin newtons per newtons (N) kilograms (kg)kilogram (N/kg)

Mercury 4 8 2

Venus 9 45 5

Earth 10 6 0.6

Mars 4 20 5

Jupiter 26 520 20

Saturn 11 132 12

Uranus 11 5.5 0.5

Neptune 12 6000 500

Pluto 4 0.005 0.00125

J-Tea&Tech.qxd 01-Apr-04 11:18 AM Page 1

J1Activity

Core

You are going to answer some questions about massand weight on different planets.

On different planets

1 The table shows the force of gravity on an object ofmass 1kg due to gravitational attraction. This iscalled surface gravity.Complete the table by filling in the missing values.The first one has been done for you.

On the Moon

2 An astronaut uses a space buggy to explore the surfaceof the Moon.a If the space buggy weighs 600N on the Moon,

what did it weigh on Earth?b What is the mass of the space buggy?

3 The astronaut collects 24kg of Moon rocks tobring back to Earth for analysis.a What will the rocks weigh when they reach

Earth?b What is the weight of these rocks on the

Moon?


J1a Gravity on the planets

RememberOn Earth, 1kg weighs 10N.

weight Surface gravity =

mass

RememberOn the Moon, thegravitational attraction isabout one-sixth that onEarth.

Planet Surface gravity Weight in Mass inin newtons per newtons (N) kilograms (kg)kilogram (N/kg)

Mercury 4 8 2

Venus 9 45

Earth 10 0.6

Mars 20 5

Jupiter 26 20

Saturn 11 132

Uranus 5.5 0.5

Neptune 12 500

Pluto 4 0.005

J-Activities.qxd 01-Apr-04 11:12 AM Page 1

J1aActivity

HelpGravity on the planets

You are going to answer some questions aboutmass and weight on the Earth and the Moon.

Apples on Earth

An apple has a mass of about 100g. On Earth it will weigh about 1N.

1 What is the mass of six apples?2 How much do six apples weigh?3 What is the mass of a box of apples that

weighs 60N?

Apples on the Moon

4 A box of apples has a mass of 6kg on Earth. What would the mass of the apples be on the Moon?

5 How much would the box of apples weighon the Moon?

Exploring the Moon

6 The astronaut uses a space buggy to explore the surface of the Moon. If the buggy weighs 600N on the Moon, what did it weigh on Earth?

7 What is the mass of the space buggy?

8 The astronaut collects 24kg of Moon rocks to bring back to Earth for analysis. What will the rocks weigh when they reach Earth?

9 What is the weight of these rocks on the Moon?


Remember1kg = 1000g

On Earth, 1kg weighs 10N.

To calculate the weight onEarth, multiply the mass by 10.

RememberOn the Moon, the pull of gravity isabout one-sixth that on Earth.

To calculate the weight of an objecton the Moon, you divide its weighton Earth by 6.


J1bTeacher

activity notesInvestigating gravity

Running the activityPupils complete the questions on the Pupil sheet using data from the Resource sheet. The Core orHelp activity should take 15–20 minutes, and the Extension activity about a further 5 minutes.

Core: Pupils answer questions including data analysis and graphical work (Question 6) to relatethe diameter of a planet and its surface gravity.

Help: The questions include data analysis but no graphical work.

Extension: The questions include data analysis and graphical work to relate the diameter of aplanet and its surface gravity, as on the Core sheet, but pupils are required to use what they havefound out to make sensible estimates. The graph from Question 6 is used to answer Question 10.

Other relevant materialSkill sheet 5: Drawing charts and graphs

Graph paper and ruler for each pupil

PitfallsYou may want to discuss the general relationships of Questions 6 and 7 to clarify understanding.

ICT opportunitiesPupils could produce their graphs using a spreadsheet such as Microsoft® Excel.

Pupils could search the Internet for more information on gravity.

AnswersCore:

1 Jupiter; 2 Jupiter; 3 Yes/no – there is a general trend suggesting this but there are exceptionssuch as Saturn, which has a higher mass than Neptune but a lower surface gravity;4 Pluto/Mercury/Mars; 5 Pluto; 6 There is no definite relationship, but there is a general trendsuggesting that there is a relationship between the diameter of a planet and its surface gravity.There are exceptions such as Saturn, which has a bigger diameter than Neptune but a lowersurface gravity. There are other exceptions. 7 Yes. Generally most of the smaller planets (thosebefore the asteroid belt) except Pluto are nearer the Sun. However, there is no size order withinthese two groups.

Extension:

8 They are not made of the same substances. 9 20 000km; (estimate: accept calculated value of (4 × 12 8003)1/3 = 20 300 km). 10 Teacher interpretation from graph – could be a wide range.

Help:

1 Jupiter; 2 Jupiter; 3 Pluto; 4 Pluto, Mars/Mercury, Venus, Earth, Uranus, Neptune, Saturn,Jupiter. No – there is a general trend suggesting that the surface gravity increases with mass, butthere are large differences in relative mass for planets, such as Saturn and Uranus, which havethe same surface gravity. 5 Pluto; 6 Jupiter; 7 Pluto, Mercury, Mars, Venus, Earth, Neptune,Uranus, Saturn, Jupiter. No – there is a general trend suggesting that surface gravity increaseswith diameter, but there are large differences in diameter for planets, such as Saturn and Uranus,which have the same surface gravity. 8 Yes, generally most of the smaller planets (those beforethe asteroid belt) except Pluto are nearer the Sun. However, there is no size order within thesetwo groups.


Type Purpose DifferentiationPaper Pupils reinforce the concept of gravitational attraction using a data interpretation exercise.

They use the information on the Resource sheet to help them to answer some questions.Core (Extension), HelpResource


J1bActivity

CoreInvestigating gravity

Planets are held in orbit around the Sun because of thegravitational attraction of the Sun on them.

You are going to find out about gravitational attraction byexamining some data about the planets in the Solar System.

Use the information on the Resource sheet to help you answer the following questions.

1 Which planet has the greatest surface gravity?2 Which planet has the greatest mass relative to Earth?3 Do you agree with the statement ‘Planets with the greatest

mass have the greatest surface area’? Explain your answer.4 Which planet has the lowest surface gravity?5 Which planet has the smallest diameter?6 Draw a graph to find out whether there is a relationship

between the diameter of a planet and its surface gravity.Explain your answer.

7 Do you agree with the statement ‘The planets in the SolarSystem can be sorted into two groups, smaller planets nearerthe Sun and larger planets further from the Sun’? Explain youranswer.


8 Explain why planets of the same size may have differentsurface gravity.

9 Estimate the diameter of a planet that has a relative mass of 4(Earth having a mass of 1) and is made of similar substances toEarth.

10 Use the graph you drew in Question 6 to estimate thediameter of a planet that has a surface gravity twice as great asthat of Earth.

Extension


J1bActivity

HelpInvestigating gravity

Planets are held in orbit around the Sun because of thegravitational attraction of the Sun on them. You are going tofind out about gravitational attraction by examining somedata about the planets in the Solar System.

Use the information on the Resource sheet to help you answer thefollowing questions.

1 Which planet has the greatest surface gravity?

2 Which planet has the greatest mass relative to Earth?

3 Which planet has the smallest mass relative to Earth?

4 List the planets in order of increasing mass (smallest mass first).Tom suggests that the greater the mass of a planet, the greaterits surface gravity. Do you agree with him completely? Explainyour answer.

5 Which planet has the smallest diameter?

6 Which planet has the largest diameter?

7 List the planets in order of increasing diameter. Meera suggeststhat the greater the diameter of a planet, the greater itssurface gravity. Do you agree with her completely? Explainyour answer.

8 Alex says ‘The planets in the Solar System can be sorted intotwo groups, smaller planets nearer the Sun and larger planetsfurther from the Sun’. Look at the third column in the table onthe Resource sheet. It gives the planets listed in order ofdistance from the Sun (nearest planet first). By comparing thiswith the list you made for Question 7, decide whether youagree with Alex. Explain your answer.



J1bActivityResourceInvestigating gravity


Planet Diameter in Approx. distance Surface gravity Relative masskilometres from the Sun in in newtons (Earth = 1) (km) millions of kilometres per kilogram

(million km) (N/kg)

Mercury 5000 60 4 0.1

Venus 12000 110 9 0.8

Earth 12800 150 10 1

Mars 7000 230 4 0.1

Jupiter 140000 780 26 320

Saturn 120000 1400 11 95

Uranus 52000 2900 11 15

Neptune 50000 4500 12 17

Pluto 3000 6000 4 0.0002

Sheet 1 of 1

ActivityResource J1b Investigating gravity

© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

Planet Diameter in Approx. distance Surface gravity Relative masskilometres from the Sun in in newtons (Earth = 1) (km) millions of kilometres per kilogram

(million km) (N/kg)

Mercury 5000 60 4 0.1

Venus 12000 110 9 0.8

Earth 12800 150 10 1

Mars 7000 230 4 0.1

Jupiter 140000 780 26 320

Saturn 120000 1400 11 95

Uranus 52000 2900 11 15

Neptune 50000 4500 12 17

Pluto 3000 6000 4 0.0002


J1cTeacher

activity notesRocketing away!

Running the activityDemonstrate some examples of rocket motion such as a car powered by a smallcarbon dioxide cylinder, a water rocket, a Stomp rocket or a model rocket froma kit. Pupils then answer the questions on the Pupil sheet to reinforce theirunderstanding of rocket motion.

Expected outcomesPupils acquire a good understanding of rocket motion.

Safety notesThe rocket car can be demonstrated in a laboratory but other demonstrationsmust be carried out outside in a large open space well away from buildings,cars, etc. Firework rockets should not be used.

Pupils must be kept at a safe distance from the demonstration.

Eye protection should be worn, except for the rocket car demonstration.

ICT opportunitiesPupils could search the Internet for information on the rockets used to launchspacecraft such as communications satellites and the space shuttle.

Answers1 a Arrow labelled M pointing to the right.

b Arrow labelled G pointing to the left.c Force of rocket car on the carbon dioxide gas to left equals force of

carbon dioxide gas on rocket car to right. (Newton’s Third Law says thatthe force on an object A due to an object B is equal and opposite to theforce on B due to A; force on rocket car to right makes car move toright.)

2 a To increase the pressure.b A downward force pushes the water out.c The force on the water pushing downwards equals the force on the water

rocket upwards (Newton’s Third Law). The upwards force on the rocketmakes it move upwards.

3 a Arrow downwards labelled weight; arrow upwards labelled thrust/forcedue to rocket engine.

b Thrust greater than weight so resultant/net force upwards; thereforerocket moves upwards.


Type Purpose DifferentiationPractical Pupils watch some demonstrations of rocket motion and then answer some questions. Core


J1cTechnician

activity notesRocketing away!

EquipmentRocket car� light model car chassis (obtainable from educational apparatus suppliers)� small carbon dioxide cylinder (e.g. as used for Sparklets soda siphons or in shooting)� sharp pointed tool (to pierce gas cylinder)� hammer

Water rocket� 2 litre plastic drinks bottle (as used for cola, lemonade, etc.)� water rocket kit (obtainable from educational apparatus suppliers)� bicycle pump� water

Model rocket� model rocket (from model shop)� firing mechanism (from model shop)� stand for rocket

Stomp rocket� Stomp rocket kit (from good toy shops)

For your informationRunning the activityDemonstrate some examples of rocket motion such as a car powered by a small carbondioxide cylinder, a water rocket, a Stomp rocket or a model rocket from a kit. Two orthree demonstrations should be provided.

Rocket carAttach the carbon dioxide cylinder to the car chassis. When the carbon dioxidecylinder is pierced the car moves very quickly across the floor in the opposite directionto the carbon dioxide gas. A clear floor area should be used for the best effect.

Water rocketThis demonstration should be done outside, on the school field or playground, wellaway from cars, etc. As air is pumped into the plastic drinks bottle it will lift off the baseand can rise to a height of 10m or so.

Model rocketThis demonstration should be done outside, on the school field. The model rocketpurchased should be suitable for the area available for launching.

Stomp rocketThis demonstration should be done outside, on the school field or playground, wellaway from cars, etc. Full instructions are provided with the kit.

Expected outcomesPupils acquire a good understanding of rocket motion.

Safety notesThe rocket car can be demonstrated in a laboratory, but other demonstrations must becarried out outside in a large open space well away from buildings, cars, etc.

Pupils must be kept at a safe distance from the demonstration.

Eye protection should be worn, except for the rocket car demonstration.


Type Purpose DifferentiationPractical Pupils watch some demonstrations of rocket motion and then answer some questions. Core


J1cActivity

CoreRocketing away!

You are going to watch some demonstrations of rocket motionand then answer the questions below.

1 The diagram shows a model of a rocket car.

a Copy the diagram and add an arrow to show the direction inwhich the car moved. Label it M.

b Add an arrow to show the direction in which the carbon dioxidegas was emitted. Label it G.

c Explain why the car moved in the direction you have shown.

2 The diagram shows a water rocket.

a Why is air pumped into the bottle of the waterrocket?

b What effect does this have on the water in thebottle?

c Why does this make the rocket move upwards?

3 The diagram shows a rocket used to launch a satelliteinto space.

a Draw a sketch of the rocket and add labelled arrowsto show the two forces acting on the rocket.

b Explain how these forces make the rocket moveupwards.

CO2


compressed air

rubberbung

water

air frompump


J2aTeacher

activity notesEscape from Earth

Running the activityPupils work through the questions on the Pupil sheet individually or in pairs,which should take them 20–30 minutes. The final question requires pupils tocomplete the story using given key words (if ICT is used the activity will takelonger to complete); this is best done individually.

You may like to review weight, mass and gravity before the start of the lesson.

Other relevant materialCatalyst 1 unit K7.

ICT opportunitiesPupils could use ICT for Question 8, e.g. word processing, DTP or presentationsoftware.

Answers1

2 It is an orbit in which a satellite appears to stay still because it orbits theEarth above the equator every 24 hours, and so remains in the same placeabove the Earth’s surface. Geostationary orbits are often used fortelecommunications satellites (for example, Sky).

3 Another type of orbit is the polar orbit, usually lower, in which thesatellite’s path goes over the Earth’s poles. Weather satellites are in polarorbits so they can scan the Earth’s surface.

4 Most likely for space observation or communication. Possibly formonitoring weather patterns on the planet or for looking for geologicaldeposits.

5 There will be less gravitational attraction on the artificial satellite if it iscompared at the same orbiting height.

6 It will take longer.

7 It has less gravitational attraction on Mars as it is further away.

8 Pupils’ stories.

force from engines weight (gravitational pull of Earth and friction (air resistance)


Type Purpose DifferentiationPaper Pupils review several different concepts first covered in Year 7 work on forces such as

weight, mass and gravity that relate to the work covered in this unit.Core


J2aActivity

CoreEscape from Earth

1 Omega 1 weighs 20000N. Draw a diagramto explain what forces Biff’s spacecraft hasto overcome to leave the ground.

2 Explain what a geostationary orbit is. Say whysuch an orbit is useful and describe one usefor a satellite in a geostationary orbit.

3 Name another type of orbit that a satellitemight use and describe the path it takesround the Earth.

4 In what ways could the artificial satelliteorbiting Mars be used?

5 Mars is a smaller planet and has less mass thanEarth. Explain how this affects the gravitationalattraction on the artificial satellite.

6 Mars is further away from the Sun than Earth.How does this affect the time it takes to orbit the Sun?

7 Does the Sun have more or less gravitational attraction on theEarth than on Mars? Explain your answer.

8 Use the following words and phrases to finish off the story.


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Biff is on the launch pad at Mission Controlon Earth, sitting in the control module of thespacecraft OOmmeeggaa 1. The countdown starts…10–9–8–7–6 initiate engines 5–4–3 releasestabilisers 2–1 blast off!

A message comes through: ‘OOmmeeggaa 11,progress to Moon Base Scorpio, land, pick upyour cargo of an artificial satellite and take itto the Tracking Station on Mars.’

After take-off Biff is told to leave the Earth’satmosphere and go around the Earth in ageostationary orbit.

The story so far …

Biff takes off once more and …Jupiter

launch force

high orbitMoon

gravitational attraction

artificial satellite

natural satellite


J3aTeacher

activity notesFamous scientists

Running the activityPupils use the Internet to answer the questions on the Pupil sheet. The activitymay be used to support pupils in their independent research.

The actual activity should last about 15–20 minutes, but pupils could spendlonger researching other aspects.

Other relevant materialThis is a useful website, but you may prefer to add others. Follow the‘Biographies’ links. Different scientists can be selected by following theinstructions given on the website once pupils have logged on to research one ofthe scientists – blupete (Peter Landry’s website).

Answers1 Copernicus

2 Galileo

3 Kepler

4 Hawking

5 Newton

6 a Galileob Newtonc Hawking

7

1400 1500 1600 1700 1800 1900 2000AD

Kepler

Copernicus

Galileo

Newton Hawking


Type Purpose DifferentiationICT Pupils develop information handling skills and become familiar with the work of some of

the most important astronomers.Core


http://www.heinemann.co.uk/hotlinks/url.asp?urlid=9603

J3aActivity

CoreFamous scientists

Our understanding of space has been helped by the work of manyfamous scientists. Some came up with very important ideas andmodels that totally changed the way people thought about the Solar System and outer space.

You are going to use the Internet to find out about six famous scientists.


Here is a website to get you started, though you may want to researchyour own sites. Follow the ‘Biographies’ links. Different scientists can beselected by following the instructions given on the website once youhave logged on to research one of the scientists – blupete (Peter Landry’swebsite).

1 Read about each scientist.2 Use the information on the websites to answer these questions.

1 Who came up with the idea that the Earth spins and also orbitsaround the Sun?

2 Who used telescopes to make important discoveries about planets?3 Who discovered that it was the pull of the Sun’s gravitational

attraction that kept the planets in their orbits?4 Who explained how the Universe began and what black holes are?5 Who developed the laws of gravity and also designed a reflecting

telescope?6 Which of the scientists listed above also did the following:

a found that the rate at which an object falls is not related to itsmass?

b discovered the three laws of motion?c based his theory upon that of Albert Einstein?

7 Make a time line showing these five scientists and theircontributions to our understanding of the Solar System.

3 If time allows, you can work in groups to prepare a shortpresentation summarising your research on one of the scientists.Each group should focus on a different scientist.

Copernicus GalileoHawking

Kepler Newton Ptolemy




J3bTeacher

activity notesEarth-centred and Sun-centredmodels

Running the activityThe ancient Greek astronomer, Ptolemy, believed in an Earth-centred universe.In the sixteenth century Copernicus, a Polish scientist, suggested that the Earthand all the other planets circle the Sun. Pupils read about these two models andthen answer some questions.

Core: Pupils answer five questions on Ptolemy and Copernicus.

Extension: In addition to the core questions pupils answer three more questionsrequiring additional understanding. Pupils should be encouraged to researchthe answers to Questions 6 and 7 if necessary.

ICT opportunitiesPupils could search the Internet for additional information on the geocentricand heliocentric models of the Solar System.

AnswersCore:

1 Ptolemy believed the Sun, the stars and all the planets rotate around theEarth on a series of celestial spheres.

2 Copernicus placed the Sun at the centre with all the planets orbitingaround it.

3 The priests argued that the Bible says that the Sun moves through theheavens and that as humans are made in God’s image we must inhabit aplanet at the centre of the Universe.

4 Kepler produced lots of measurements of the movement of the planetswhich supported Copernicus’s model.

5 Yes/no with consistent reasons. For example:

– Yes – because it was simpler and easier to understand than Ptolemy’smodel; the mathematical arguments were very persuasive; Kepler’sexperimental evidence was strong.

– No – because the Bible says that the Sun moves through the heavens; theChurch must be right; Ptolemy’s model had been around for a long timeand explained what was seen.

Extension:

6 Earth rotates around the Sun but we are on Earth so we think we arestationary and the Sun is moving.

7 Jupiter takes a lot longer than Earth to go around the Sun, so seen fromEarth there are times when Jupiter appears to go backwards. (You may needto discuss the diagram showing how Mars appears to go backwardssometimes when viewed from Earth to help some pupils to answer thisquestion.)

8 Newton meant that he was building on the discoveries of scientists whohad lived before him.


Type Purpose DifferentiationPaper Pupils read about the two models of the Solar System and then answer some questions. Core (Extension), Resource


J3bActivity

CoreEarth-centred and Sun-centredmodels

The ancient Greek astronomer, Ptolemy, believed in an Earth-centred universe. In the sixteenth century Copernicus, a Polishscientist, suggested that the Earth and all the other planetsorbit the Sun. You are going to read about these two modelsand answer some questions.

Read the information on the Resource sheet and look carefully atthe diagrams.

1 Describe the main features of Ptolemy’s geocentric model.

2 Describe the main features of Copernicus’s heliocentric model.

3 Why did Copernicus’s model upset the Church?

4 What further evidence was obtained to support theSun-centred model?

5 Imagine you lived in the sixteenth century and heard aboutCopernicus’s ideas. Would you have believed him? Give tworeasons to support your decision.


6 Explain why we seem to see the Sun rotating around theEarth.

7 Ptolemy’s observation that Jupiter appears to move backwardswas correct. He explained the peculiar motion of Jupiter in acomplicated way. Use the diagram of Earth and Mars on theActivity resource sheet to help you to explain how theSun-centred model accounts for Jupiter’s apparent backwardsmotion.

8 Newton said, ‘I am only standing on the shoulders of giants’when he was congratulated for his ideas about the heliocentricmodel. What do you think he meant?

Extension


J3bActivityResourceEarth-centred and Sun-centred

models

Ptolemy

Ptolemy believed the Sun, the stars and all the planetsrotate around the Earth on a series of celestial spheres. Hemade careful drawings and calculations to show how hismodel agreed with what he and other astronomersobserved when they looked at the night sky.

His model worked but was very complicated. For instance,he observed that Jupiter appears to move backwards atcertain times in its orbit. He explained this by saying thatJupiter moved in epicycles (orbits around orbits). The moreobservations he made, the more complicated hisexplanations became.

Copernicus

Copernicus realised that explanations could be made much simpler if theSun was placed at the centre withall the planets, including Earth,orbiting around it. He was soon introuble though because this ideawent against the teaching of theChurch. The priests argued thatthe Bible says that the Sun movesthrough the heavens and that ashumans are made in God’s image we must inhabit a planet at the centre of the Universe.

Copernicus’s model explains epicycles because planets such as Mars and Jupitertake much longer than Earth to orbit the Sun. This means their line of sight fromEarth changes direction, accounting for the ‘loops’ that we see. Kepler made lots ofmeasurements of the movement of the planets which supported Copernicus’smodel. Galileo, an Italian scientist, was put under house arrest by the CatholicChurch for writing a book saying he agreed with Copernicus.

Over a hundred years after Copernicus first developed his Sun-centred model,Isaac Newton explained how gravity holds the planets in orbits around the Sun. Hewas able to use his ideas to do calculations that agreed with Kepler’s experimentalobservations. At long last, Copernicus had been proved right!


s

1

1

22

33

44

5 566

7

7Earth

Marssix Earth months later

one Earth month later

sight-line from Earth to Mars now

7

3

64

5

2

1


J4aTeacher

activity notesResearching Moon birth

Running the activityPupils use the Internet to find out about one of the theories.

The four theories are:

1 the spin theory2 the capture theory3 the double planet theory4 the giant impact theory.

Divide the class into four groups. Ask each group to find out about one of thetheories. Each group then prepares a poster/fact sheet/presentation for the restof the class.

Other relevant materialThese are suitable websites, though you may want to use others or ask pupils toresearch their own sites. Use the search facility on each site to search for ‘Moonbirth’.

Space website

StudyWorks! website


Type Purpose DifferentiationICT Pupils use the Internet to find out about one of the theories on how the Moon was

formed. They then prepare a poster/fact sheet/presentation for the rest of the class.No pupil sheets




J4bTeacher

activity notesActing out Moon birth

Running the activityWorking in small groups pupils produce a role play to illustrate one of thetheories of how the Moon formed.

Divide the class into groups and tell each group which theory it is going toact out.

Suggest a suitable plan for the pupils:

� Choose people to represent the Earth and the Moon.

� Decide how you are going to act out the birth of the Moon, according to thetheory you are going to demonstrate.

� Write a commentary to accompany your role play. This should include anintroduction, an explanation of what is going on as the Moon is formed anda summing up that includes the evidence ‘for’ and ‘against’ the theory.

After each group has acted out its role play, pupils can vote for the group thatgave the best performance.


Type Purpose DifferentiationDiscussion Working as part of a small group pupils produce a role play to illustrate one of the theories

of how the Moon formed.Core


J4bActivity

CoreActing out Moon birth

Working as part of a small group you are going to role playone of the theories of how the Moon formed.

1 Your teacher will divide the class into groups and tell youwhich theory you are going to act out.

2 Use the guidelines below to help you plan your role play.� Choose people to represent the Earth and the Moon.� Decide how you are going to act out the birth of the

Moon, according to the theory you are going todemonstrate.

� Write a commentary to accompany your role play. Thisshould include an introduction, an explanation of what isgoing on as the Moon is formed and a summing up thatincludes the evidence ‘for’ and ‘against’ the theory.

3 After each group has acted out its role play, vote for the groupthat gave the best performance.


Sheet 1 of 1

ActivityCoreJ4b Acting out Moon birth

Working as part of a small group you are going to role playone of the theories of how the Moon formed.

1 Your teacher will divide the class into groups and tell youwhich theory you are going to act out.

2 Use the guidelines below to help you plan your role play.� Choose people to represent the Earth and the Moon.� Decide how you are going to act out the birth of the

Moon, according to the theory you are going todemonstrate.

� Write a commentary to accompany your role play. Thisshould include an introduction, an explanation of what isgoing on as the Moon is formed and a summing up thatincludes the evidence ‘for’ and ‘against’ the theory.

3 After each group has acted out its role play, vote for the groupthat gave the best performance.




J1 PlenariesA massive problem

Review learningPupils match the masses of various objects to their weighton different planets, given the surface gravities of theplanets.

Sharing responsesPupils discuss their responses to Activity J1a. Make sure anywrong calculations or misconceptions are clarified.

Group feedbackPupils work in groups to discuss their responses to ActivityJ1b. If pupils carried out this activity at different levels(Core, Help, Extension) it would be useful to arrange thegroups accordingly.

Word gameOrganise the class into groups of three.

Give each pupil in the group one of the word pairs (seeopposite). Ask them to think about what links/connects thetwo words and in what ways are they different.

Pupils then discuss their ideas with other pupils who havealso been given that word pair. Scan the class during thisphase.

Pupils return to their original groups. Each group memberthen shares his or her information. Groups summariseinformation on OHT/PowerPoint/as individual notes.

Looking aheadPupils complete diagrams to show the forces on a rocket atvarious points on its journey from Earth to the Moon. (Red only)

➔ Pupil sheet

Answers2 kg → Neptune; 6 kg → Mars; 50 kg →Earth; 0.5 kg → Jupiter; 400 kg → Venus

Word pairsmass/weightSun/starrocket/jetEarth/Jupiterforce/gravityplanet/moon

➔ Pupil sheet

Answers


Review learning

Pupils match the massesof various objects to theirweight on differentplanets, given the surfacegravities of the planets.

Sharing responses

Pupils discuss their responsesto Activity J1a.

Group feedback

Groups of pupils discusstheir answers to ActivityJ1b and report back to theclass.

Word game

Pupils discuss word pairs(e.g. mass/weight,rocket/jet, Earth/Jupiter,Sun/star)

Looking ahead

Pupils complete diagrams toshow the forces on a rocketat various points on itsjourney from Earth to theMoon. (Red only)

Earth

Moon

J-Plenaries.qxd 01-Apr-04 11:20 AM Page 1


Review learning

Draw lines to link each mass with its correct weight. (Use theinformation in the table above to help with any calculations youneed to do.)

Mass Weight

2 kg 500 N on Earth

6 kg 3600 N on Venus

50 kg 24 N on Mars

0.5 kg 24 N on Neptune

400 kg 13 N on Jupiter


Planet Surface gravity in newtons per kilogram (N/kg)

Mercury 4

Venus 9

Earth 10

Mars 4

Jupiter 26

Saturn 11

Uranus 11

Neptune 12

Pluto 4



Looking ahead

The diagrams show a rocket at various points on its journeyfrom the Earth to the Moon.

Add arrows to each diagram to show the forces acting onthe rocket at each stage of its journey. The length of eacharrow should represent the size of each force (e.g. a longline means a big force).


Remember

On the Moon, the pull ofgravity is about one-sixththat on Earth.

Earth

Earth

Earth

Moon

Moon

Moon



J2 PlenariesSatellites

Review learning� Pupils answer a set of true/false questions on satellites.

Sharing responses� Pupils discuss their responses to the questions in Activity J2a.

� Ask pupils to list the key things necessary to put a satellitein orbit.

Group feedback� Ask ‘What am I?’ Remind pupils they can only ask closed

questions that can be answered with ‘yes’ or ‘no’. Theyhave to determine the answer with as few questions aspossible.

Word game� Invite a volunteer pupil up to the front of the class to list as

many things as possible related to the lesson in 30 seconds.

� Write the suggestions on the board.

� Ask for further volunteers until most of the key words havebeen listed.

Looking ahead� Ask pupils to answer the question, ‘How do we know the

Earth is round?’, by suggesting evidence they could observe.

� Collate evidence on the board (e.g. a ship can sail aroundthe Earth and return to its starting point, pictures takenfrom space).

➔ Pupil sheet

Answers1 true; 2 false; 3 false; 4 true; 5 true; 6 true; 7 true

Words/conceptssatellite; Moon; Sun; Earth; Jupiter;geostationary satellite; artificial satellite;Sputnik; gravitational attraction;communications satellite; polar orbit;Hubble telescope


Review learning

True/false quiz on factsabout satellites.

Sharing responses

Pupils discuss theirresponses to Activity J2a

Group feedback

Play ‘What am I?’ game. Thewinning group is the one withthe most correct answers in theallotted time.

Word game

Invite volunteer pupil tolist as many things aspossible related to thelesson in 30 seconds.

Looking ahead

Ask the question: ‘How dowe know the Earth isround?’


J2 PlenariesSatellites

Review learning

Decide if the following statements are true or false.

1 Sputnik 1 was the first artificial satellite. [True/False]

2 There is no gravity acting on a satellite. [True/False]

3 A geostationary satellite does not move. [True/False]

4 A polar orbit goes over the North and South Poles. [True/False]

5 The Moon is a natural satellite of the Earth. [True/False]

6 To stay in orbit a satellite has to be travelling fast. [True/False]

7 Venus is a satellite of the Sun. [True/False]

Sheet 1 of 1

Sheet 1 of 1


PlenariesJ2 Satellites

Review learning

Decide if the following statements are true or false.

1 Sputnik 1 was the first artificial satellite. [True/False]

2 There is no gravity acting on a satellite. [True/False]

3 A geostationary satellite does not move. [True/False]

4 A polar orbit goes over the North and South Poles. [True/False]

5 The Moon is a natural satellite of the Earth. [True/False]

6 To stay in orbit a satellite has to be travelling fast. [True/False]

7 Venus is a satellite of the Sun. [True/False]




J3 PlenariesThe Solar System

Review learning� Hand out the Pupil sheets. Ask pupils to have a go at

answering as many questions as they can. Make it clearthat the harder questions are towards the end.

� When pupils have had 5 minutes to answer the questions,go over the answers with the class.

Sharing responses� Divide pupils into groups. Each group makes a short

presentation to summarise their research in Activity J3a.

Group feedback� In groups, pupils write an argument for and against each

of the two models. Ask groups to present their arguments.List important points for and against each model on theboard.

Word game� Ask pupils to complete the wordsearch on the Pupil sheet.

� Ring the words on a copy of the Pupil sheet and show it asan OHT for pupils to check their answers. Use the wordson it to revise the lessons in the unit.

Looking back� Pupils revise and consolidate knowledge from the unit.

� They can use the Unit map, Pupil checklist or the Testyourself questions.

➔ Pupil sheet

Answers£100, Sun; £500, nine; £1000, Sun-centred;£5000, geocentric/Earth-centred; £10 000,Galileo; £50 000, Polish; £100 000,Newton; £500 000, Galileo; £1000 000,Kepler

➔ Pupil sheet

➔ Unit map

➔ Pupil checklist

➔ Test yourself


Review learning

Pupils play a ‘millionaire’quiz.

Sharing responses

Each group makes a shortpresentation to summarise theirresearch in Activity J3a.

Group feedback

In groups, pupils write anargument for and againsteach of the two models ofthe Solar System.

Word game

Wordsearch using keywords from the unit tocheck progress.

Looking back

Pupils revise andconsolidate knowledge fromthe unit.



Review learning

Try and answer as many questions as you can. The questions getharder as you work down the sheet.


£ Question Answer

100 What is the name of the star that is nearest to Earth?

500 How many planets are there in the Solar System?

1000 What does heliocentric mean?

5000 What model did Ptolemy describe?

10 000 Who developed the first telescope?

50 000 What nationality was Copernicus?

100 000 Who explained Kepler’s observations with ideas about gravity and mass?

500 000 Name the Italian scientist who was imprisoned for supporting the heliocentric model.

1 000 000 Who made many observations and calculations to work out that planets’ orbits are ellipses (flattened circles)?



Word game

All these words are connected with the unit so far. See how manyof them you can find in the wordsearch.


W O G S E N R U T A S H B

E S O P R U Y C E A R T H

I G G M A S S O K T K E S

G N R O L V T T C P A N P

H A A O O D F A O E N A A

T T V N P C F O R C E L C

S U I W G H T B A E O P R

A R T I F I C I A L R M J

X A Y W F S Y R U C R E M

P L U T O H M Y A S K B E

mass weight rocketstarSun

planetEarth gravityforceSaturn

Moon artificial MercuryPlutonatural



J4 PlenariesBirth of the Moon – Think about

Group feedback� Pupils have 5–10 minutes to discuss, write down or display

what they have learned about models in general, the need forevidence to support a model and how it may need to bemodified or abandoned as further evidence is obtained.

Bridging to other topics� Ask pupils to think of other areas of science where a model has

been replaced as further methods of obtaining evidence aredeveloped.

� Other areas could include the model of particle movement insolids, liquids and gases (if not discussed fully in the Starteractivity), the model of particle movement in heat transfer byconduction and convection, the model of an electric current orthe atomic model (a positively charged nucleus with orbitingelectrons) if pupils have come across it.


Group feedback

Pupils have 5–10 minutes to discuss, write down or display what theyhave learned about a model, the need for evidence to support it and howthe model may need to be modified or abandoned as further evidence isobtained.

Bridging to other topics

Ask pupils to think of other areas of science where a model has beenreplaced as further methods of obtaining evidence are developed.


J1 SpecialsA massive problem

1 Look at this cartoon then answer the questions about Jemma.

a Is Jemma’s mass different in different places?

b Is Jemma’s weight different in different places?

c Does Jemma weigh more on the Earth or on the Moon?

d Where does Jemma have no weight?

e Which has the greatest gravitational attraction – the

Earth or the Moon?

2 Use some of these words to fill in the gaps.

a The Sun is the object in our Solar System.

It has the mass. The pull of the Sun’s

on the planets keeps the Solar System together.

b The further away a planet is from the Sun, the

the gravitational attraction between them.

c To escape from the Earth, rockets need to push with

a greater than their .


largestsmallest thrust greatest

weight weaker stronger gravity

J-Specials.qxd 28-Apr-04 7:45 PM Page 1

J1 SpecialsA massive problem (continued)

3 Look at this information about some planets and the Moon.

Now answer these questions.

a On which of them will Gemma have the smallest weight?

b On which planet will Gemma weigh the most?

c is the planet with the largest gravity.

This is because it is the planet with the largest .


1kg = 4N

Earth

1kg = 10N

Moon

Mars

1kg = 1.7N

Jupiter

1kg = 26N


J2 SpecialsSatellites

1 Draw lines to match the words to their meanings.


the Moon

artificialsatellite

geostationary

orbit

gravity

polar orbit

2 Match the words below to their descriptions.

a These help ships, planes and cars know where they are on

the Earth.

b These are satellites where astronauts and cosmonauts

live and work.

c These send radio, TV and telephone messages around

the world.

navigation satellites

communication satellites exploration satellites

observation satellites space stations

A satellite that stays in the sameplace over the Earth’s surface.

The Earth’s natural satellite.Other planets have moons too.

The path a satellite takes over theEarth’s North and South Poles.

The path a satellite or the Moontakes around the Earth.

A machine launched into space by people.

The force that keeps satellites in orbit.


J3 SpecialsThe Solar System

1 Write true or false for each sentence.

a The Earth is at the centre of the Universe.

b Galileo used telescopes to see Jupiter’s moons.

c There have been many models over time to explain the Solar

System.

d The heliocentric model, with the Sun at the centre of the Solar

System, is the one we use today.

2 Draw lines to match the scientist to their ideas.


Ptolemy (200AD)

Copernicus(1473–1543)

Brahe(1546–1601)

Galileo(1564–1642)

Newton(1642–1727)

Kepler(1571–1630)

The first scientist to suggest the Sunis at the centre of the Solar System.

He made accurate star charts, whichshowed how the planets moved.

An Egyptian astronomer who drew theUniverse with the Earth at the centre.

He worked out that the planets’orbits are flattened circles.

He made and used telescopesto see Jupiter’s moons.

He used the idea of gravity andthe masses of objects to explainwhy the planets orbit the Sun.


J4 SpecialsBirth of the Moon

1 Here are some names of theories of how the Moon was formed. Write the name of the correct theory next to its description below.


The double planet theory (1950s) The capture theory (1909)

The spin theory (1878)The giant impact theory (1975)

a The Earth was hit by a huge object. Some material of the outer surface of the Earth was blasted into space. This material came together to form the Moon.

b As the Earth formed, it spun so fast that a lump was thrown off. This lump cooled and formed the Moon.

c The Moon was formed somewhere else. It came too close to the Earth and was captured by the Earth’s gravity.

d The Moon was formed in the same way as the planets formed. This happened at the same time as the Earth was formed.

2 In question 1 the year each theory was put forward is given after itsname. Put the theories in order of age, oldest first.

3 Write true or false for each sentence.

a Moon rocks have been brought back to the Earth.

b 80 pounds of Moon rock were brought back to Earth.

c The Moon rocks contain lots of iron.

d The capture theory is the one most scientists believe today.


J Specials answersGravity and space

J1 A massive problem1 a no

b yesc on the Earthd in spacee the Earth

2 a largest, greatest, gravitational attractionb weakerc thrust, weight

3 a Moonb Jupiterc Jupiter, mass

J2 Satellites1 the Moon – The Earth’s natural satellite. Other

planets have moons too.artificial satellite – a machine launched intospace by people.orbit – The path a satellite or the Moon takesaround the Earth.gravity – The force that keeps satellites in orbit.geostationary – a satellite that stays in the sameplace over the Earth’s surface.polar orbit – The path a satellite takes over theEarth’s North and South Poles.

2 a navigation satellitesb space stationsc communication satellites

J3 The Solar System1 a false

b truec trued true

2 Ptolemy (200 AD) – An Egyptian astronomerwho drew the Universe with the Earth at thecentre.Copernicus (1473–1543) – The first scientist tosuggest the Sun is at the centre of the SolarSystem.Galileo (1564–1642) – He made and usedtelescopes to see Jupiter’s moons.Brahe (1546–1601) – He made accurate starcharts, including how the planets moved.Kepler (1571–1630) – He worked out that theplanets’ orbits are flattened circles.Newton (1642–1727) – He used the idea ofgravity and the masses of objects to explain whythe planets orbit the Sun.

J4 Birth of the Moon1 a The giant impact theory (1975)

b The spin theory (1878)c The capture theory (1909)d The double planet theory (1950s)

2 The spin theory (1878), The capture theory(1909), The double planet theory (1950s), Thegiant impact theory (1975)

3 a trueb truec falsed false


Spe Answers.qxd 6/23/2004 9:19 AM Page 10

J1 HomeworkA massive problem

HELP

1 Look at the diagram below. It shows five planets, drawn to the same scale.

a i Which planet will have the greatest gravitational attraction?

ii Which planet will have the smallest gravitational attraction?

iii Will the gravitational attraction on planet C be larger or smallerthan the gravitational attraction on planet E?

b All the planets are affected by the Sun’s gravitational attraction.

i Which planet is most affected by the Sun’s gravitational attraction?

ii Will the effect of the Sun’s gravitational attraction on Planet Bbe smaller or larger than on Planet D?

iii Copy and complete the following sentence, referring to youranswer to question 1 b, part ii.

I think my answer to the question is correct because … .

c Yuri is an astronaut. In an experiment, wearing his spacesuit, he jumps as high ashe can on the Earth. He travels to the Moon and jumps as high as he can there.

i Does he jump higher on the Earth or on the Moon?

ii Where does he weigh more, on the Moon or on the Earth?

CORE

2 Yuri, the astronaut in the last question, travels on through the Solar System. He stops off at all the planets shown in the diagram in question 1.

a i On which planet will he weigh the most?

ii Explain why he will weigh the most on this planet.

b i Yuri has a mass of 82 kg on the Earth. What is his mass on Planet D?

ii Explain why Yuri’s weight is not the same on Planet D and on theEarth, given that the Earth is smaller than Planet D.


A B C D ETo the Sun

J-Homework.qxd 28-Apr-04 10:58 AM Page 1

J1 HomeworkA massive problem (continued)

c i What units are used to measure Yuri’s weight?

ii What do these units tell you about what weight is?

d i Yuri’s rocket has a mass of 3 000 500 kg on the Earth. Explain whyit needs very powerful rocket engines to get it into orbit round the Earth.

ii Explain why Yuri’s rocket needs less powerful engines as it movesaway from the Earth.

EXTENSION

3 The table shows some data about some of the moons around Jupiter.


Name Date of Distance from Diameter in discovery Jupiter in km km

Amalthea 1892 181000 170

Callisto 1610 1800000 4800

Europa 1610 671000 3100

Ganymede 1610 1100000 5300

Himalia 1904 11500000 185

Io 1610 422000 3600

Thebe 1979 222000 100

a Which of the moons has the greatest gravitational attraction?

b Which of the moons experiences the smallest gravitational attractionfrom Jupiter?

c The moons all have a more or less circular orbit around Jupiter. Usingideas about balanced forces explain why they stay in this orbit.

d i Suggest a reason why Callisto, Europa, Ganymede and Io werediscovered before any of the others.

ii These four moons were discovered by Galileo. Why was Galileoable to see them when other scientists before him did not?

e Explain whether or not it would be correct to say that the gravitationalfield of Ganymede has no effect on the orbit of Callisto.


J2 HomeworkSatellites

HELP

1 Match the beginning of each sentence with the correct ending. Writeout each complete sentence.


Beginnings Endings

A Communication satellites are used to 1 are called navigation satellites.

B Observation satellites can 2 send telephone messages around the world.

C The type of satellites used by ships to 3 are called space stations.find their position on the Earth

D Exploration satellites can 4 take detailed photographs of the Earth.

E The type of satellites where astronauts 5 take very clear pictures of the planets.can live and work in space

2 a Give the name of one natural satellite of the Earth.

b What keeps this natural satellite from flying off into outer space?

c Give one difference between this natural satellite and the Earth.

CORE

3 Telstar was the first artificial satellite to be put into Earth orbit. It couldbe seen crossing the night sky, from north to south. It took about 15 minutesto cross from the northern horizon to the southern horizon.

a i What type of orbit was being used by Telstar?

ii Explain how its position in the night sky would have been different,if it had been in the other type of orbit.

b i Telstar could be seen as a bright object moving across the nightsky on a clear night. It had no lights. Explain why it could be seen so clearly.

ii Telstar also crossed the sky during the day but could not be seen.Explain why not.

c i Telstar was used to carry live television pictures across the globe.Times were booked in advance. Sometimes, if the programme overran,the pictures suddenly cut out. Explain why this happened.

ii What is the advantage of modern communication satellites,compared with those in orbits like Telstar?


J2 HomeworkSatellites (continued)

d Which of the following satellites would normally be in geostationaryorbits around the Earth?

A – exploration satellites B – navigation satellites

C – communication satellites D – the Moon

EXTENSION

4 Look at the diagram showing forces acting on the Moon as it orbitsthe Earth.

a What would happen to force A if the speed of the Moon decreased?

b If the speed of the Moon did decrease, what would happen tothe Moon?

c Explain how forces A and B together are responsible for keepingthe Moon in its orbit round the Earth.

d Explain why the Moon orbits the Earth, rather than having its ownorbit around the Sun.

e When the Apollo missions went to the Moon their speed decreasedas they moved away from the Earth and then increased as theyapproached closer to the Moon. Use your knowledge about gravitationalattraction to explain why this happened.


Earth

MoonA

B


J3 HomeworkThe Solar System

HELP

1 a Match the name of the astronomer to the work that has made them famous.


A Made very accuratestar charts andworked out howMars moved.

C First person to saythat the planets goround the Sun.

E Worked out thatthe planets orbitthe Sun in ellipses.

B Drew a model thatshowed the Sunand planets goinground the Earth.

D Observed thatJupiter's Moonsorbited Jupiter andnot the Earth.

Galileo

Kepler

Ptolemy

Copernicus

Brahe

b i What model of the Solar System has the Earth at its centre?

ii What model of the Solar System has the Sun at its centre?

iii Which model was Galileo supporting when he was put in prisonby the Roman Catholic Church?

CORE

2 a Explain how Galileo’s observations about Jupiter’s moons helped himto decide which model of the Solar System was probably correct.

b Explain why the ancient Greeks had not been able to use the sameinformation as Galileo when they drew their model of the Solar System.

c Explain how Isaac Newton’s work on gravitational attraction helpedhim to explain how the planets moved round the Sun.

d Describe where the orbit of the Moon would have to go in thegeocentric model of the Solar System.

e i What technical developments in astronomical observations helpedEuropean astronomers to find out more about the orbits of the planets?

ii Modern astronomy can locate objects much further away thanthose in our Solar System. What type of instrument is often used today,to track far distant objects in space?

f How has the discovery of other galaxies helped to support theheliocentric model of our own Solar System?


J3 HomeworkThe Solar System (continued)

EXTENSION

3 Imagine that you are standing on the surface of Neptune,looking towards the Sun. You are interested in the heliocentricand geocentric theories about the Solar System.

a i Describe what you would see if you observed the Earthand its Moon over a period of 28 days.

ii Which theory about the Solar System would yourobservations support and why?

b i At some stage during your observations, you would notbe able to see the Earth at all. Explain why not.

ii Which model of the Solar System does this observationsupport and why?

iii Explain how this observation could be used to support theother theory about the Solar System.

c i On Neptune you are reasonably close to Jupiter. You cansee many of its moons. Describe what you would see overa period of an Earth year.

ii Which model of the Solar System does this observationsupport and why?

d From the observations described in these questions suggestwhich theory about the Solar System is more likely to becorrect, explaining the reason for your choice.



J1Homework

mark schemeA massive problem


HELPQuestion Answer Mark

1 a i E 1

ii A 1

iii Smaller 1

b i A 1

ii Larger 1

iii I think my answer to the question is correct because B is nearer to the Sun than D/B is larger than D. Underscore is pupil response. 1

c i Higher on the Moon. 1

ii On the Earth. 1

Total for Help 8

COREQuestion Answer Mark

2 a i E 1

ii It is the biggest so has the largest gravitational attraction. 1

b i 82 kg 1

ii Planet D pulls him downwards/towards its centre more than the Earth, 1so his weight is greater than on the Earth. 1

c i Newtons 1

ii It is a force. 1

d i They have to produce a larger force upwards 1than the gravitational attraction pulling it downwards. 1

ii The Earth’s gravitational attraction decreases as he gets further away from it. 1

Total for Core 10

EXTENSIONQuestion Answer Mark

3 a Ganymede 1

b Himalia 1

c The force created by their movement is balanced by the gravitational attraction of Jupiter 1so they are held in a circular orbit by the two opposite forces. 1

d i They are much larger so can be seen more easily. 1

ii He had a telescope. 1

e It is not correct 1because all objects exert a gravitational attraction on all other objects. 1

Total for Extension 8


J2Homework

mark schemeSatellites



1 Complete sentences are: A 2; B 5; C 1; D 4; E 3. 1 mark each 5

2 a The Moon. 1

b Gravitational attraction. 1

c One from: smaller/no atmosphere/less gravitational attraction/no 1 water/no life.

Total for Help 8


3 a i Polar orbit. 1

ii It would have seemed to stay in the same place in the sky. 1

b i It reflected light 1from the Sun. 1

ii The sunlight was so bright that it masked the reflection. 1

c i The satellite had moved below the horizon 1so signals could no longer reach it. 1

ii They do not move below the horizon/they stay in the same place above the Earth. 1

d B and C. 2

Total for Core 10


4 a It would get smaller. 1

b It would fall towards the earth. 1

c They are balanced/the same size 1so the Moon neither flies away from the Earth nor falls towards it. 1

d It is closer to the Earth than to the Sun 1so the Earth’s gravity has more effect upon it. 1

e As they left the Earth and after the rockets had shut down the Earth’s gravity slowed them down. 1As they reached the Moon the Moon’s gravitational attraction began to pull on the rocket and accelerate it towards the Moon. 1Accept other equivalent responses.



J3Homework

mark schemeThe Solar System



1 a The correct links are: Galileo – D; Brahe – A; Kepler – E; Copernicus – B; Ptolemy – C. 5Award 1 mark for each correct link.

b i The geocentric system. 1

ii The heliocentric system. 1

iii The heliocentric system. 1

Total for Help 8


2 a He saw that the moons orbited Jupiter 1and not the Earth 1so concluded that not everything was in orbit around the Earth. 1

b They had no telescopes/could not see very much of the Solar 1System. Accept equivalent responses.

c He was able to explain why the planets stayed in their orbits 1due to the gravitational attraction of the Sun. 1

d It would have to go round the Sun. 1

e i They were able to make better and better telescopes. 1

ii Radio telescopes/the Hubble space telescope. 1

f It has shown that there are other star systems in space like ours. 1

Total for Core 10


3 a i The Moon would orbit the Earth once in 28 days. 1

ii Supports the geocentric theory because the Earth is at the centre of the Moon’s orbit. 1

b i It would be on the other side of the Sun. 1

ii The heliocentric model because the Earth must be orbiting the Sun to get onto the other side of it. 1

iii The Sun could be orbiting the Earth and have moved to the near side of the Earth, supporting the geocentric theory. 1

c i The moons would orbit Jupiter. 1

ii The heliocentric model because it shows that not all heavenly bodies orbit the Earth. 1

d The heliocentric model because the heliocentric model can explain all the evidence. 1



J Test yourselfGravity and space

1 Calculate the weight of these objects on the Earth (gravitational field strength = 10 N/kg):

a a 5 kg bag of potatoes

b a 70 kg man

c an 80 g orange.

2 Fill in the gaps with the correct word, mass or weight, in each of these statements.

a stays the same everywhere in the solar system.

b is less on the Moon than on the Earth.

c is measured in kilograms and

is measured in newtons.

d is a force.

e acts towards the centre of the Earth.

3 The gravitational field strength at the surface of Mars is 3.7 N/kg.

a How much would a 1 kg bag of sugar weigh on Mars?

b How much would a 65 kg person weigh on Mars?

c If a person weighs 560 N on Earth, how much would they weigh

on Mars?

4 The diagram shows the Sunand the Earth.

a What is the almost circularpath of the Earth called?

b What force keeps theEarth moving in this path?

c On the diagram draw an arrow showing the force. Label it F.

d Imagine that the force is suddenly switched off. What will happen to the Earth?

e Draw this new path on the diagram.


Earth

Sun

Test-Qust.qxd 6/25/2004 10:33 AM Page 27

J Test yourselfGravity and space (continued)

5 The diagrams show two very large objects with the same mass.

In which diagram, A or B, is the gravitational force between the

objects larger?

6 The diagrams show two planets and their moons. In which diagram,

A or B, is the gravitational force between the objects larger?

7 The diagram shows the journey of a rocket from the Earth to the Moon.

a Why does a rocket need a large thrust on take-off from the Earth?

b What happens to the force of gravity as the distance between the rocket and the Earth increases?

c What would happen if the thrust of the rocket at take-off was not enough to put the rocket in orbit around the Earth?


A B

10 × mass of Earth

0.5 × massof Earth

10 000 km

A

moon

planet planet

10 × mass of Earth

0.9 × massof Earth

10 000 km

B

moon

Earth

Moon


J Test yourselfGravity and space (continued)

8 Complete the sentence.

The Moon is a natural of the Earth.

9 Fill in the gaps to complete these sentences about satellites.

a If a satellite is in a orbit, it stays at the same

point above the Earth’s surface. It takes 24 hours to complete an orbit –

the time the Earth takes to rotate once. This is very useful for satellites

which are used for .

b If a satellite is in a orbit, it passes over

the poles of the Earth. This is very useful for satellites which are

used for .

10 Draw lines to match the scientist with his work on the solar system.

Newton � � a geocentric model of the universe

Copernicus � � very accurate star charts and planet positions

Galileo ��

calculation to show that planets move in elliptical orbits round the Sun

Kepler � � observation of Jupiter’s moons using a telescope

Brahe � � explanation of elliptical orbits

Aristotle � � a heliocentric model of the universe



JTest yourself

AnswersGravity and space

1 Calculate the weight of these objects on the Earth (gravitational field strength = 10 N/kg):

a a 5 kg bag of potatoes

b a 70 kg man

c an 80 g orange.

2 Fill in the gaps with the correct word, mass or weight, in each of these statements.

a stays the same everywhere in the solar system.

b is less on the Moon than on the Earth.

c is measured in kilograms and

is measured in newtons.

d is a force.

e acts towards the centre of the Earth.

3 The gravitational field strength at the surface of Mars is 3.7 N/kg.

a How much would a 1 kg bag of sugar weigh on Mars?

b How much would a 65 kg person weigh on Mars?

c If a person weighs 560 N on Earth, how much would they weigh

on Mars?

4 The diagram shows the Sunand the Earth.

a What is the almost circularpath of the Earth called?

b What force keeps theEarth moving in this path?

c On the diagram draw an arrow showing the force. Label it F.

d Imagine that the force is suddenly switched off. What will happen to the Earth?

e Draw this new path on the diagram.

It would move in a straight line, along a tangent.

gravity

orbit

207.2 N

240.5 N

3.7 N

Weight

Weight

weightMass

Weight

Mass

0.8 N

700 N

50 N


Earth

F

Sun

Test-Ans.qxd 16-Jun-04 2:55 PM Page 27

JTest yourself

AnswersGravity and space (continued)

5 The diagrams show two very large objects with the same mass.

In which diagram, A or B, is the gravitational force between the

objects larger?

6 The diagrams show two planets and their moons. In which diagram,

A or B, is the gravitational force between the objects larger?

7 The diagram shows the journey of a rocket from the Earth to the Moon.

a Why does a rocket need a large thrust on take-off from the Earth?

b What happens to the force of gravity as the distance between the rocket and the Earth increases?

c What would happen if the thrust of the rocket at take-off was not enough to put the rocket in orbit around the Earth?

It would fall back to Earth.

It decreases.

To escape the pull of gravity back to Earth.

B

A


A B

10 × mass of Earth

0.5 × massof Earth

10 000 km

A

moon

planet planet

10 × mass of Earth

0.9 × massof Earth

10 000 km

B

moon

Earth

Moon


JTest yourself

AnswersGravity and space (continued)

8 Complete the sentence.

The Moon is a natural of the Earth.

9 Fill in the gaps to complete these sentences about satellites.

a If a satellite is in a orbit, it stays at the same

point above the Earth’s surface. It takes 24 hours to complete an orbit –

the time the Earth takes to rotate once. This is very useful for satellites

which are used for .

b If a satellite is in a orbit, it passes over

the poles of the Earth. This is very useful for satellites which are

used for .

10 Draw lines to match the scientist with his work on the solar system.

Newton � � a geocentric model of the universe

Copernicus � � very accurate star charts and planet positions

Galileo ��

calculation to show that planets move in elliptical orbits round the Sun

Kepler � � observation of Jupiter’s moons using a telescope

Brahe � � explanation of elliptical orbits

Aristotle � � a heliocentric model of the universe

forecastingweather

polar

communications

geostationary

satellite



JEnd of unit test

GreenGravity and space

1 Write ‘true’ or ‘false’ for each of these statements:

a The force of gravity keeps all the planets moving around the Sun. 1 mark

b The force of gravity can be a pulling or a pushing force. 1 mark

c On Earth, the force of gravity attracts everything towards thecentre of the Earth. 1 mark

d Some planets and moons have no air because they have no gravity. 1 mark

2 Ali uses the bathroom scales to find that he has a mass of 50 kg.

a What is his weight in newtons? Choose the correct letter. 1 markA 5 NB 50 NC 500 ND 5000 N

b What would his weight (in the same clothes) be in a lunar moduleon the Moon? Choose the correct letter. 1 markA the same as on the EarthB nothingC more than on the EarthD less than on the Earth

c What is his mass on the Moon? Choose the correct letter. 1 markA 50 kgB 0 kgC 83.3 kgD 8.3 kg

d Describe how jumping on the Moon would be different fromjumping on the Earth. 1 mark

3 This diagram shows the path taken by the Moon, which is in orbitaround the Earth:


Earth

Moon

J-L-EUTest.qxd 18-Jun-04 11:00 AM Page 1

JEnd of unit test

GreenGravity and space (continued)

a Which of these reasons explains why the Moon moves aroundthe Earth? Choose the correct letter. 1 markA It is very heavy and cannot stop.B There is a magnetic attraction between the Moon and

the Earth.C The force of gravity pulls the Earth and the Moon towards

each other.D The force of gravity pushes the Moon round.

b A rocket is launched from Earth. It travels straight up away fromthe Earth and keeps going. (The Moon is on the opposite sideof the Earth from where the rocket took off.)

What happens to the force of gravity on the rocket?Choose the correct letter. 1 markA It gets bigger.B It stays the same.C It gets smaller.

4 The planet Jupiter is the largest in the solar system. It hasseveral moons.

a What keeps the moons moving around Jupiter? 1 mark

b Jupiter is much bigger than Earth. What would happen to yourweight on Jupiter? 1 mark

5 Write down all the things in the list below which could be changedin order to change the force of gravity between two objects. 3 marks� the hardness of the objects� the mass of one of the objects� the mass of the other object� squashing one of the objects into a smaller volume� the distance between the objects� the temperature of both of the objects

6 The planet Venus has a mass of only about 0.8 times the mass ofthe Earth.

a What effect would this have on the gravitational field strengthof Venus compared with that of the Earth? 1 mark

b Would a rocket need more or less thrust to take off from Venusthan from the Earth? 1 mark



JEnd of unit test

GreenGravity and space (continued)

7 This satellite has been put into an orbit where it rotates at exactly thesame rate as the Earth and stays overhead at the same place on Earth.

a What is this type of orbit called? 1 mark

b Give an example of a way we use this type of satellite. 1 mark

c Satellites in lower orbits move quickly across the Earth’s surface.What could they be used for? 1 mark

8 There have been two models of the Solar System. One was calledthe geocentric model. The Earth is the centre of the universe andeverything moves around it. The other is called the heliocentricmodel. The Sun is the centre of the Solar System, and the Earthorbits around the Sun.

If you sit in your garden on a sunny day, the Sun appears to moveacross the sky.

a Which of the two models does this evidence support? 1 mark

Galileo used his telescope to observe that Jupiter had moons.The moons appeared to move around Jupiter, not the Earth.

b i Which of the two models does this evidence support? 1 mark

The idea of the geocentric model lasted over 1000 years. It wasthe work of scientists like Copernicus and Galileo that started todisprove the model.

ii What was it about their evidence that started to disprovethis model? 1 mark

The picture shows star trails around a star called the Pole Star. The Pole Star seems to stand still while the stars rotate slowly around it.

c i Which model of the Solar Systemdoes this evidence support? 1 mark

ii Explain how this evidencesupports that model. 1 mark


Earth

Pole Star


JEnd of unit test

RedGravity and space

1 Ali uses the bathroom scales to find that he has a mass of 50 kg.

a Using the value for gravitational field strength g = 10 N/kg,calculate his weight in newtons. 1 mark

b What would his weight (in the same clothes) be in a lunarmodule on the Moon? Choose the correct letter. 1 markA the same as on the EarthB nothingC more than on the EarthD less than on the Earth

c What is his mass on the Moon? Choose the correct letter. 1 markA 50 kgB 0 kgC 83.3 kgD 8.3 kg

2 Write down all the things in the list below which could be changedin order to change the force of gravity between two objects. 3 marks� the hardness of the objects� the mass of one of the objects� the mass of the other objects� squashing one of the objects into a smaller volume� the distance between the objects� the temperature of both of the objects

3 The planet Venus has a mass of only about 0.8 times the mass of the Earth.

a What effect would this have on the gravitational field strength ofVenus compared with that of the Earth? 1 mark

b Would a rocket need more or less thrust to take off from Venusthan from the Earth? 1 mark

4 This satellite has been put into an orbit where it rotates at exactly thesame rate as the Earth and stays overhead at the same place on Earth.

a What is this type of orbit called? 1 mark

b Explain why this is useful. 1 mark


Earth


JEnd of unit test

RedGravity and space (continued)

5 Geological companies looking for oil or minerals use satellites tosurvey the Earth.

a What type of orbit would be suitable for this satellite? 1 mark

b Explain your choice. 1 mark

6 This diagram shows the path taken by a rocket on a trip to the Moon.

a Where is the gravitational force on the rocket greatest? 1 mark

b Where might the gravitational force on the rocket be zero? 1 mark

c Explain your answer to b. 1 mark

7 Look at this table.

a Calculate the weight of a 50 kg person on Jupiter. 1 mark

b Using the data from the table, compare the gravity on Mercuryand on Jupiter, describing how your weight would vary. 2 marks


Earth

A

E

Moon

C

D

B

Object Diameter (km) Mass (number of Gravity at thetimes the mass surface (N/kg)of the Earth)

Sun 1390000 968 000 274

Mercury 4880 0.06 3.7

Earth 12800 1 9.8

Mars 6780 0.11 3.7

Jupiter 143000 318 23.2

Uranus 48600 15 8.7

Pluto 2300 0.002 0.6


JEnd of unit test

RedGravity and space (continued)

c A robot explorer has been sent to Mars. After its mission it musttake off from Mars to return to Earth. The robot explorer has a massof 100 kg.

i To launch the robot from Mars, the force of gravity on the robotexplorer would have to be exceeded. What is the force of gravityon the robot? 1 mark

ii Some people are concerned that a large amount of fuel willbe needed to provide this thrust (force) throughout the wholejourney. In fact this is not the case. Explain how the force onthe robot changes during the journey. 1 mark

8 There have been two models of the Solar System. One was calledthe geocentric model. The Earth is the centre of the universe andeverything moves around it. The other is called the heliocentricmodel. The Sun is the centre of the Solar System, and the Earth orbitsaround the Sun.

The picture shows star trails around a star called the Pole Star. ThePole Star seems to stand still while the stars rotate slowly around it.

a i Which model of the Solar System does this evidence support? 1 markii Explain how this evidence supports that model. 1 mark

Scientists who study space are called astronomers. They share theirdata and observations with other astronomers all over the world.

b Why is this important to people who are developing theoriesand models? 1 mark

Our Moon is very different from most moons. Astronomers havepuzzled over its origin for many years. In 1969, the first astronautslanded on the Moon.

c i What sort of evidence could astronomers collect about the Moonbefore 1969? 1 mark

ii In what way did this evidence change after 1969? 1 mark


Pole Star


JEnd of unit test

mark schemeGravity and space


Green (NC Tier 3–6)Question Answer Mark Level

1 a True 1 3

b False 1 3

c True 1 4

d False 1 4

2 a C 1 5

b D 1 5

c A 1 5

d It requires less effort or you would go higher. 1 5(Do not credit ‘float’ or ‘easier’.)

3 a C 1 4

b C 1 5

4 a The force of gravity. 1 4

b It would be bigger. 1 5

5 The mass of one of the objects. 1 6

The mass of the other object. 1 6

The distance between the objects. 1 6

Deduct one mark for each incorrect answer up to three.

6 a The gravitational field strength of Venus would beless than that of Earth. Allow 0.8 times. 1 6

b It would need less thrust on Venus. 1 6

7 a Geostationary 1 5

b Communications or other correct example. 1 4

c Surveying or other correct example. 1 4

8 a Geocentric 1 4

b i Heliocentric 1 5ii It was based on data from observations

made of planets and their moons. 1 5

c i Heliocentric 1 6ii The stars do not appear to be going around

the Earth. The Pole Star would also moveif the geocentric model were true. 1 6

Scores in the range of: NC Level

4–6 3

7–11 4

12–16 5

17–25 6


JEnd of unit test

mark schemeGravity and space


Red (NC Tier 5–7*)Question Answer Mark Level

1 a 500 N 1 5

b D 1 5

c A 1 5

2 The mass of one of the objects. The mass of the other object.The distance between the objects. Deduct one mark for eachincorrect answer up to three. 3 6

3 a The gravitational field strength of Venus would be lessthan that of Earth. Allow 0.8 times. 1 6

b It would need less thrust on Venus. 1 6

4 a Geostationary 1 5

b It can be communicated with all the time or it doesn’tdisappear round the other side of the Earth. 1 6

5 a Low Earth orbit. 1 6

b Can travel all over Earth’s surface or can see more detailbecause closer to Earth. 1 6

6 a A 1 7

b C 1 7

c At a certain point (closer to the Moon than the Earth)the force from the Earth is equal and opposite to theforce from the Moon. As the rocket travels further fromEarth the force of gravity between the rocket and Earthdecreases. As it gets closer to the Moon the force of gravitybetween the rocket and the Moon increases. 1 7*

7 a 50 kg × 23.2 kg/N = 1160 N One mark for correct answer 1 5and unit without showing working.

b The gravity on Mercury is less than the gravity on Jupiter. 1 7

Weight would be less on Mercury than on Jupiter ormore on Jupiter than on Mercury. 1 7

c i 370 N 1 7ii The force of gravity on the robot becomes less as it gets

further from the planet. 1 7*

8 a i Heliocentric 1 6ii The stars do not appear to be going around the Earth.

The Pole Star would also move if the geocentric model were true. 1 6

b They have lots of evidence to work with. 1 6

c i Indirect evidence using telescopes and instruments on Earth. 1 7ii Direct evidence from the moon including rock samples. 1 7

Scores in the range of: NC Level

6–10 5

11–15 6

16–18 7

19–25 7*


J Pupil checklistGravity and space


Learning outcomes I can do I can do I need to this very this quite do more well well work on this

I can explain how gravitational attraction depends on mass.

I can explain how gravitational attraction depends on the distance between two masses.

I know that weight varies on different planets.

I can explain how rockets are launched from Earth into space.

I can describe how the forces on rockets or satellites vary as they travel away from the Earth.

I can explain how satellites stay in orbit.

I know the difference between natural and artificial satellites.

I can give some uses of artificial satellites.

I can describe the two main models of the Solar System.

I can explain which model is now accepted as true.

I can understand that scientific ideas change over time as new discoveries are made.

I can describe theories about the birth of the Moon.

I can name the theory about the Moon that is now believed to be true.

I can explain why this theory is thought to be correct.

I can explain why the other theories are not believed to be correct.

Pupil-Checklist.qxd 17-Jun-04 8:00 PM Page 10

J GlossaryGravity and space


Word


geocentric model

geostationary orbit

heliocentric model

natural satellite

polar orbit

satellite

thrust

volatile R

Definition

The pushing force of a rocket or engine.

An object that orbits a larger object.

A satellite that is made by people, such as a communicationssatellite.

A satellite that is made by nature, such as the Moon orbitingthe Earth.

The path around the Earth taken by a satellite travelling atthe same speed at which the Earth rotates.

The path taken by a satellite passing over the North andSouth Poles of the Earth.

A model of the universe with Earth at the centre andeverything, including the Sun, moving around it.

A model of the Solar System with the Sun at the centre andthe planets moving around it.

Easily vaporised at normal temperatures. R

Glossary.qxd 18-Jun-04 11:33 AM Page 11

J Key wordsGravity and space


geocentric model

geostationary orbit

heliocentric model

natural satellite

polar orbit

satellite

thrust

volatile R


geocentric model

geostationary orbit

heliocentric model

natural satellite

polar orbit

satellite

thrust

volatile R

Sheet 1 of 1

Sheet 1 of 1


Key wordsJ Gravity and space


Keywords.qxd 18-Jun-04 11:35 AM Page 10


J Book answersGravity and space

J1 A massive problemGreena 66 kgb Jupiterc Planet A, because it is closer to the star.1 a false

b truec trued false

2 a 30 000 000 Nb The force upwards of 35 000 000 N was

greater than the weight downwards of therocket.

3 a The greater the mass of the objects the larger is the gravitational attraction between them.

b The greater the distance between two objects,the less is the gravitational attractionbetween them.

Reda Joe’s weight would be 0 N.b i 1300N

ii 450Nc 13950Nd i The weight will become less.

ii The amount of thrust needed will be less.e Because the moon has less mass, its gravitation

force of attraction is less. The closer distance ofthe Moon to position 2 makes its force ofattraction greater, to balance.

f The force on the rocket is much greater on Earth because it is close to Earth. When it is 354 000 km away from Earth the force of the Earth’s gravitational attraction is much less.

1 a 30 385 000 Nb 30 380 000 Nc 3 352 900 N

2 The larger the distance between two objects, theweaker the gravitational attraction.

3 a decreasingb increasingc decreases

J2 SatellitesGreena An object made by people that orbits a larger

object.b Any of the planets, other than Earth.c It slowed down.1 a Gravitational attraction.

b It falls out of orbit to Earth.2 a An orbit that passes over the North and

South poles.b An orbit in which the satellite travels at the

same speed as the Earth is turning on its axis.

This makes the satellite stay at the same placeover the Earth.

c A satellite used for radio, TV andtelecommunication.

3 Risks of collision are greater with more satellites.

Red1 a Gravitational force.

b It falls to Earth.c It flies off into space.

2 a A satellite in a geostationary orbit remains inone place over the Earth. It can be used forcommunications.

b A satellite in a polar orbit can be used tophotograph all parts of the Earth.

3 Risks of collisions are greater with moresatellites.

4 a An advantage is that activities which requirelight can continue during night time hours.One disadvantage is that people’s biorhythmswill be upset by the change from night andday pattern to an all day pattern.

b

J3 The Solar SystemGreena i Moving around the Earth.

ii At the centre of the universe.b Individual answers.c He made telescopes.d Because the heliocentric model was correct.1 The geocentric model put the Earth at the

centre of the Solar System with the Sun, Moon,planets and stars moving around the Earth. The heliocentric model put the Sun at the centre of the Solar System with the Earth andother planets revolving in circular orbits around the Sun.

2 a Created the geocentric model of the SolarSystem.

b Created the heliocentric model.c Kepler worked out that the orbits of planets

around the Sun were ellipses rather thancircles.

NIGHT TIME

DAY TIME

light fromSun

Russiancity

giantmirror

Book Answers.qxd 18-Jun-04 12:44 PM Page 26


J Book answersGravity and space (continued)

3

Reda The apparent sizes of the Sun and Moon would

suggest that their distances from the Earth arequite similar.

b The regular changes as day and night suggestthat either the Sun goes around the Earth once aday, the Earth goes around the Sun once a day,or the Earth spins on its axis once a day. The lastidea is the correct one. The seasons suggest thatthe Earth is closer to the Sun during the summerand the Earth is further away from the Sun inthe winter. However this is not the correctexplanation. The tilt of the Earth on its axisrelative to its orbit around the Sun actuallycauses the seasons to occur.

c i One would expect, considering only themasses of the planets, that a 1 kg mass

would weigh much more on Saturn than onEarth. This is because the mass of Saturn is somuch greater than the mass of the Earth, andgravitational forces of attraction are greaterwhen the masses of the bodies are greater.

ii The 1 kg mass weighs about the same on bothplanets because the radius of Saturn is somuch greater than the radius of the Earth. Thegreater distance of the mass from the centre ofthe planet Saturn makes the gravitationalforce of attraction much smaller, but thegreater mass of Saturn makes the gravitationalforce of attraction greater, so they balance.

1 Individual answers.2 Data and observations supply facts and

information which must fit theories andpredictions and calculations.

Ancient Greeksand Egyptian Ptolemybelieved Earth atcentre of universe.

Copernicus put Sunat centre with planetsgoing round Sun.

Galileo made telescopesand supported heliocentricmodel; imprisoned by Church.

Kepler worked outshapes of planets'orbits as ellipses.

Newton showedhow gravity works.

Tyco Brahe made accurateobservations of planets'and stars' motions.

350 BC 1500 AD 16301580 1590 1680

Ancient Greeks,Thales, Pythagoras,Aristotle believedEarth spherical andat centre of universe.

Aristarchus thought Earth revolved around Sun but idea didn'tcatch on.

Galileo made telescopesand saw moons orbit Jupiter and saw Saturn's rings. He was convinced that Copernicus's heliocentric model was correct and was imprisoned by the Church as a result.

Kepler used Brahe's observations and set out laws and equations of planetary motion.

Newton showed why Kepler's laws worked and explained gravity.

Tyco Brahe made accurateobservations and star charts.

350 BC 300 BC 1500 AD 1580 16301590 1680

Copernicus suggested heliocentric model, as did Aristarchus.

3



J Book answersGravity and space (continued)

J4 Birth of the MoonGreena i The double planet theory.

ii The spin theory.iii The capture theory.

b The capture theory.c Yes. If they were formed in the same way they

would have similar structures and chemicals.d i Material from the outer surface of the Earth,

which contained almost no iron, was blastedoff into space by the collision of the hugeobject with Earth.

ii The material blasted off from the Earth,which eventually formed the Moon, camefrom the surface of the Earth, so the rocks onthe Moon are very similar to the rocks on thesurface of the Earth.

1 The spin theory, the capture theory, the doubleplanet theory and the giant impact theory.

2 The scientists were able to get samples of rocksfrom the Moon.

3 There was never any evidence that the Earth hadspun fast enough to ‘spin off’ a lump the size ofthe Moon.

4 They had the Moon rocks analysed and foundtheir composition to be similar to thecomposition of the rocks in the surface of the Earth.

Reda The spin theory.b The double planet theory.

c The spin theory suggests that the Moon’s rockswould be similar to the Earth’s surface rocks.The capture theory would indicate that therocks from Earth and Moon would be verydifferent. The double planet theory suggests thatthe composition of the Earth and Moon shouldbe very similar. But the density of the Moon ismuch less than that of the Earth which isstrange if they formed at the same time.

d The capture theory.e i The material used to form the Moon had

come from the surface of the Earth, whichcontains little iron.

ii The material used to form the Moon hadcome from the surface of the Earth.

iii On collision with the Earth, the collidingbody caused very high temperatures to form. The material ripped off the surface ofthe Earth and which formed the Moon hadall of the volatile substances boil off intospace.

1 Only evidence which was visual, by telescopes.2 Astronauts landed on the Moon and were able

to bring back rock samples.3 The capture theory and double planet theory

were incorrect, as the rocks were analysed to be similar to the rocks on the surface of theEarth.

4 Their conclusions were based completely onmathematical calculations and did not involvethe chemical composition of the Earth and Moon.


Documents

J Gravity and space Unit guide - Physicslocker Index · 2013-09-16 · unit 7K Forces and their effects and unit 7L The Solar System and beyond. ... J Gravity and space Unit guide