Checkpoint Science Workbook 1 answers.pdf

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1 THE CHARACTERISTICS OF LIVING THINGS

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You may award one mark for each answer or part of an answer.

1

_{The characteristics of living things}

Living and never lived

1

1 a)a) Never lived; it has come out of the Earth. b)

b) Once alive; it is the skin of an animal. c)

c) Living; it shows all the characteristics of life. d)

d) Once alive; it is formed from wood that is produced by trees.

Signs of life

2 2 a)a) 3

b)

b) Feeding – rabbit is eating grass; sensitivity – ears face a sound and the rabbit stops eating;_{movement – the rabbit hops away.}

Animal life

3

3 a)a) Examples could include a crab or lobster. b)

b) Shed it (moult). c)

c) It is softer. d)

d) It takes in water to stretch it. e) e) Gills.

Plant life

4 4 a)a) Reproduction. b)

b) Movement and growth. c)

c) Light, carbon dioxide, water, small amounts of chemicals in the soil.

Eating and feeding

5

5 a)a) Use the same mass of clay for each tooth; drop them from the same height. b)

b) Examples could include a cat or dog. c)

c) Examples could include a rabbit or sheep.

Respiration

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2 MAJOR ORGAN SYSTEMS

Movement

7 7 a)a) Muscles. b)

b) To find food, avoid enemies, find shelter. c)

c) Pump blood around the body. d)

d) Churn up food to help it digest.

Irritability

88Skin – touch; eyes – sight; ears – hearing; nose – smell; tongue – taste.

Growth and

Growth and reproductio

reproduction

n

9 9 a)a) Abena. b) b) Chipo. c) c) 85 cm. d)

d) Abena 48 cm, Bisa 45 cm, Chipo 50 cm, Doli 45 cm. e)

e) Abena 5 cm, Bisa 5 cm, Chipo 3 cm, Doli 5 cm. f)

f) The elephants grow most in their early years and their growth slows down as they get older and almost stops by 20 years of age.

g)

g) About 207 cm.

Excretion

10 a)

10 a) Urine, sweat, air we breathe out. b) b) inhaled air passes through this tube exhaled air passes through this tube breathe in and out gently here limewater c) c) Limewater. d)

d) Limewater changes from clear to cloudy or milky. e)

e) Respiration.

2

_{Major organ systems}

Organs of a ﬂowering plant

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2 MAJOR ORGAN SYSTEMS c) c) Make food. d) d) The flower. e) e) The stem. f)

f) Help grip other supports to hold up a weak stem.

Organ systems of a human

2

2 In any order. a)

a) Heart – circulatory system. b)

b) Lungs – respiratory system.

Skeleton and movement

3

3 Ligament – fibres – hold bones together; cartilage – hard slippery surface – lets bones move easily and reduces wear; synovial fluid – liquid – lubricant reduces friction.

4

4 The action of one muscle produces an opposite effect to the other muscle and causes movement in the opposite direction.

Circulatory system

5 5 a)a) 3, 1, 4, 2 b)

b) A throbbing sensation or artery.

Respiratory system

6 6 a)a)

Age in years

Age in years Breaths per minuteBreaths per minute

0 30 3 25 6 20 18 15 24 15 b) b) 5 5 10 10 3 3 6 6 9 9 112 2 115 5 118 8 221 1 2244 15 15 20 20 25 25 30 30 0 0 Age/years Age/years B r e a t h s p e r m i n u t e 0 0 c)

c) 17.7 breaths per minute. d)

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3 CELLS

Digestive system

7 7 a)a) Salivary gland, oesophagus, stomach, small intestine, large intestine. b) b) Abdomen. c) c) Stomach.

Nervous system

8 8 a)a) Brain. b) b) Spinal cord. c) c) Electrical.

Excretory system

9 9 a)a) kidney ureter bladder b)

b) Either or both kidneys. c)

c) Urea.

Sensory system

10 a)

10 a) Nose, ear, skin, eyes. b)

b) To provide information about your surroundings.

Endocrine system

11 a) 11 a) Glands. b) b) Insulin. c) c) Diabetes. d)

d) By taking extra insulin into the body.

3

_Cells

The microscope

1 1 a)a) A sunless part of the sky. b)

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3 CELLS

d)

d) Stage clips. e)

e) Is in the centre of the hole on the stage. f)

f) Moves away from the specimen on the slide. 2 2 Numbers 4, 5, 2, 1, 3.

Looking at cells

3 3 a)a) cell wall cell wall cell membrane cell membrane vacuole vacuole chloroplast chloroplast cytoplasm cytoplasm nucleus nucleus b)

b) Nucleus, cytoplasm, cell membrane. 4 4 a)a) DNA. b) b) In the nucleus. c) c) Genetic material. d)

d) It gives an organism its features. 5

5 a)a)

T

Tiimme e iin n hhoouurrss NuNummbbeer r oof f cceellllss

0 8 1 16 2 32 3 64 4 128 b)

b) The number of cells doubles every hour. c) c) 256

Adaptations in ce

Adaptations in cells

lls

6 6 a)a)

Red blood cell Red blood cell

phagocyte phagocyte

nucleus nucleus

b)

b) Red blood cell. c)

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4 MICROORGANISMS

7 7 a)a) Smooth muscle cells. b)

b) In the walls of the oesophagus, stomach or intestines. c)

c) Nerve cells. d)

d) Any one from: nerves, spinal cord, brain. 8

8 a)a) In the throat lining. b)

b) Cilia. c)

c) Wave to and fro and carry dust trapped in mucus away from the lungs. 9

9 a)a) On the surface of a plant root. b)

b) Takes up water from the soil.

Cells, tissues, organs and organisms

10

10 A group of the same kind of cells that do a special task. 11 a)

11 a) An organ system is a group of organs that perform a vital task in the survival of the body. b)

b) An organism is formed from all the organs and organs systems that make up a body.

4

_{Microorganisms}

The fungi kingdom

11Heat, cold and dry conditions. 2 2D, B, C, A 3 3 a)a) 0 0 10 20 30 40 50 Temperature of sample/°C H e i g h t o f f r o t h / m m 60 5 10 15 20 25 30 35 40 45 50

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5 LIVING THINGS IN THEIR ENVIRONMENT

b)

b) Used the same amount of yeast, sugar and water to make each sample. c)

c) Carbon dioxide. d)

d) Respiration. e)

e) The sample at 0 °C was still alive at that temperature and started respiring when the temperature rose. The sample at 50 °C had been killed at that temperature and so could not respire at a lower temperature.

The Monera kingdom

44 Spherical, spiral or rod-like.

5 5 a)a) Any two from: diphtheria, whooping cough, cholera, typhoid, tuberculosis, food poisoning. b)

b) Examples could include yoghurt or cheese.

The Protoctista kingdom

6 6 a)a) They make their own food by photosynthesis like plants. b)

b) They feed as animals do.

77 Any two from: malaria, sleeping sickness, amoebic dysentery.

Viruses

88 Virus sticks to cell – 1; virus enters cell – 2; protein coat breaks down – 3; DNA released – 4; DNA reproduces – 5; protein coat forms around DNA – 6; cell wall breaks down – 7.

9

9 Any two from: the common cold, influenza, chicken pox, measles, rabies, AIDS.

Decomposer

10 a)

10 a) Bacteria and fungi. b)

b) Minerals. c)

c) The plants take up minerals in the soil water and use them to grow.

5

_{Living things in their environment}

Ecology

11

Factor

Factor Abiotic Abiotic BioticBiotic

temperature ✔

animals eating leaves ✔

trees making shade ✔

wind speed ✔

rainfall ✔

birds using leaves for nesting materials ✔

humans walking through the habitat ✔

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5 LIVING THINGS IN THEIR ENVIRONMENT

Food chains

3

3 a)a) Plant➔_snail➔_shrew➔_hawk.

b)

b) The plant. c)

c) An animal that eats only plants. d)

d) The snail. e)

e) No. An omnivore is an animal that eats both plants and animals. The food chain only shows the animals to be either herbivores or carnivores.

Biodiversity

4

4 a)a) The number of individuals of the species of moth in the habitat. b)

b) Checking the level of the population by comparing the numbers he has counted at the site. 5

5 a)a)

yoghurt pot

leaves and soil ground pebbles wood cover b) b) The cover. c)

c) The smooth walls of the yoghurt pot do not let them climb out. d)

d) The beetle and centipede have fallen into the trap and the centipede has eaten the beetle. e) e) 0 0 10 10 s l u g s s n a i l s b e e t l e s Species Species N u m b e r o f i n d i v i d u a l s s p i d e r s a n t s 20 20 30 30 6 6 a)a) Rock pool 1. b) (i)

b) (i) It goes down. (ii)

(ii) It goes up. c) (i)

c) (i) Mussels. (ii)

(ii) The numbers are greatly reduced where starfish are found. The numbers of the other animals do not change.

d)

d) (i)(i) They cannot survive the drier conditions. (ii)

(ii) They have eaten all the mussels. e)

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6 PEOPLE AND THE PLANET

Adaptations

7 7 a)a) (i)(i) A and B (ii) (ii) A and D (iii) (iii) B and C b) b) B c) c) D d) d) C 88 Darkness.

99 Aestivation is when animals rest (sleep) for a time in a hot dry season. Hibernation is when animals rest (sleep) for a time in cold winter conditions.

10 a)

10 a) Eggs➔_larva➔_pupa➔_adult➔_{in a circle.}

b)

b) X marked at egg and pupa. 11 a)

11 a) Any two from: storing water, thick waxy covering to prevent water loss, spikes to prevent animals biting in for a drink, long roots to find water.

b)

b) Any three from: can drink large amounts of water, thick foot pads for heat insulation, webbed feet to stop sinking in sand, holds body on long legs above hot desert surface, can shut nostrils to keep out sand, long eyelashes keep sand from eye, third eyelid for wiping away sand, strong teeth for grinding tough desert plants, fat in hump is an energy store.

12

12 It traps a bubble of air under its wings. 13 a)

13 a) (i)(i) Strong for grinding up plants. (ii)

(ii) On the side of the head to see all around. (iii)

(iii) Large to catch sounds and movable to detect sounds from all directions. b) (i)

b) (i) Conical shape for stabbing. (ii)

(ii) Facing forwards so they overlap and allow distances to be judged.

6

_{People and the planet}

Early times to People today

11 Hunter gathering – 1; farming – 2; invention of water mill – 3; invention of windmill – 4; invention of steam engine – 5; invention of electrical generator – 6.

2

2 a)a) Any two from: coal, oil, gas, nuclear fuel. b)

b) Any two from: wind, water, geothermal, solar energy, biofuels. 3 3 a)a) Petrol, diesel, kerosene.

b)

b) Carbon dioxide.

Changes in the environment

4 4 a)a) The ground surface is ripped up. b)

b) Coal, metal ores. 5

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7 CLASSIFICATION AND VARIATION

6

6 a)a) It absorbs heat radiated from the Earth. b)

b) Carbon dioxide is a greenhouse gas produced when fuels are burnt in transport, in factory work and in many power stations.

7

7 a)a) Oxygen. b)

b) It screens out harmful rays from the Sun. c)

c) Over the North and South Poles. d)

d) CFCs in fridges, air conditioning and aerosol sprays. e)

e) The governments in 196 countries have agreed to reduce their use.

Time to save the planet?

8

8 a)a) (i)(i) Glass. (ii) (ii) Plastic. (iii) (iii) Metal. (iv) (iv) Cardboard. (v) (v) Paper. b) (i) b) (i) 4900 kg. (ii) (ii) 2400 kg. c)

c) The campaign has reduced the demand for landfill sites. d)

d) Paper. e)

e) Putting out more waste paper bins or a similar solution.

7

_{Classification and variation}

Classifying living things

1 1

F

Feeaattuurre e PPllaanntt AAnniimmaall

Cannot make own food ✔

Has cellulose for support ✔

Has chlorophyll ✔

Can move about ✔

Dividing up the animal kingdom

2

2 a)a) Any three from: A has a shell, B doesn’t; A has a head, B doesn’t; B has five limbs, A doesn’t have any limbs; A has tentacles, B doesn’t.

b) b) G Grroouupp AA BB Jellyﬁsh Annelid worms Molluscs ✔ Echinoderms ✔

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8 THE STATES OF MATTER

Verteb

Vertebrates

rates

3

3 a)a) Order, family, genus, species. b)

b) Species.

The plant kingdom

4 4 a)a) Mosses. b) b) Ferns.

Variati

Variation

on

5 5 C

Coonnttiinnuuoouus vs vaarriiaattiioonn DDiissccoonnttiinnuuoouus vs vaarriiaattiioonn

A, B, D, E C, F

6 6 a)a)

6 6

JJaan n FFeeb b MMaar r AAppr r MMaay y JJuun n JJuull Months Months M a s s / g A

Auug g SSeep p OOcct t NNoov v DDeecc 7 7 8 8 9 9 10 10 11 11 b)

b) The mass decreases early in the year then builds up in the latter part of autumn then decreases again through the winter.

c) c) Small. d)

d) A bat. It builds up a food store in its body, which it uses up during hibernation. e)

e) Continuous. f)

f) The environment.

8

_{The states of matter}

Comparing the states of matter and The particle theory of

Comparing the states of matter and The particle theory of matter

matter

1

1 Easy to compress. 2

2 a)a) Box A should be packed with circles touching or almost touching each other. Box B should contain very few particles with plenty of space between them. b)

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9 PROPERTIES OF MATTER AND MATERIALS

3

3 a)a) Raise its temperature to its melting point. b)

b) It loses its fixed shape and starts to flow. c)

c) They receive more energy. d)

d) The solid particles vibrate to and fro but when melting occurs they slide over each other. e)

e) Freezing. 4

4 a)a) Identical containers were used; the same amount of liquid was put in each one; they were left for the same length of time.

b) b) B c)

c) Warm and windy. d) d) C e) e) At the surface. f) f) High energy. g) g) A gas. 5

5 a)a) Gas bubbles form inside it and rise to the surface. b)

b) Boiling point. c)

c) It boils faster. 6

6 a)a) By cooling down a gas. b)

b) On dust particles in the air. 7

7 a)a) Liquid. b)

b) The solid sulfur inside the volcano sublimes in the heat and becomes a gas. It rises out of the volcano, cools, sublimes and forms a solid on the side of the volcano.

8

8 a)a) A solute is a solid that dissolves in a solvent. A solvent is a liquid that dissolves the solute. b)

b) In the gaps between the liquid particles.

9

_{Properties of matter and materials}

Introducing elements

1

1 a)a) A substance made from just one kind of atom. b)

b) A group of atoms of one or more elements.

Metals and non-metals

2 2 a)a)

S

Suubbssttaannccee MMeettaall NNoonn--mmeettaall

A ✔

B ✔

b)

b) Oxygen, nitrogen. c)

c) Metals usually have shiny surfaces. 3

3 Carbon – barbecue charcoal; chlorine – keeping swimming pools water clean; iodine – portable water purifying kits; phosphorus – matches; sulfur – car tyres.

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9 PROPERTIES OF MATTER AND MATERIALS

Metal alloys

4

4 Bronze – copper and tin – bells; brass – copper and zinc – ornaments; steel – iron and carbon – car bodies.

The properties of materials

5

5 a)a) A – rigid, brittle, transparent. B – opaque, absorbent, flexible. C – translucent, rigid, heat insulator. D – opaque, flexible, electrical conductor.

b) b) D c) c) A 6 6 a)a) A ruler. b)

b) Drop the ball bearing from the same height above each material and measure the width or depth of the impression it leaves in the material.

7 7 a)a) 12%, 10%, 20%, 8%. b) b) A A B B CC Cloths Cloths % i n c r e a s e i n m a s s D D 0 0 5 5 10 10 15 15 20 20 c) c) C, A, B, D. d)

d) He could have used samples of cloth that all had a mass of 100 g.

Comparing the properties of

Comparing the properties of materials

materials

8

8 a)a) It is malleable – can be pressed into a shape; it is a good conductor of heat; it is waterproof. b)

b) It is a heat insulator; it is soft enough to be carved into shape; it is rigid. 9

9 a)a) B b) b) C

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10 ACIDS AND ALKALIS c) c) 1 2 3 4 5 6 7 8 Time/min T e m p e r a t u r e / ° C 0 10 20 0 30 40 d) d) 7.4 minutes.

10

_{Acids and}

_{Acids and alkalis}

_alkalis

Early acids and alkalis

1

1 Acid – sour; alkali – the ashes.

Acids

2

2 methanoic – nettles; citric – lemon; lactic – exercising muscles; tartaric – grape; hydrochloric – mammal stomach.

Alkalis

3

3 a)a) Because they can burn the skin. b)

b) Alkalis.

Detecting acids and alkalis

44Boyle.

The pH scale

55Litmus – red – blue; Methyl orange – pink – yellow; phenolphthalein – colourless – pink. 6

6 a)a) X is on 7. b)

b) The circle is around 0–2. c)

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11 ROCKS AND SOIL

Neutralisation

77 acid + akali➔_{salt + water}

8

8 a)a) nitric acid + sodium hydroxide➔_{sodium nitrate + water}

b)

b) sulfuric acid + potassium hydroxide➔_{potassium sulfate + water}

c)

c) hydrochloric acid + sodium hydroxide➔_{sodium chloride + water}

9

9 sodium hydrogen carbonate + hydrochloric acid➔_{sodium chloride + carbon dioxide + water}

10 a)

10 a) Soap, because the sting is acidic and soap is alkaline. b)

b) Vinegar, because the sting is alkaline and vinegar is a weak acid. 11 a)

11 a) The stomach makes too much acid as it digests food. b)

b) It dissolves to make an alkaline solution, which neutralises the acid. 12 a)

12 a) It contains two solids, which will only react together when they dissolve in water. b)

b) Carbon dioxide, which makes the texture light.

Acid rain

13 a)

13 a) East and south east. b)

b) South west and west. c)

c) The south west, since all the recordings were 6, which is slightly acid. No other direction had as many readings of 6.

d)

d) Recording event 4, north east contaminated with acid and recording event 8, north west contaminated with alkali.

11

_{Rocks and soil}

From Big Bang to the Sun

11 Big Bang – hydrogen and helium; Nebula making stars – carbon, nitrogen, oxygen; supernovas – gold lead, platinum.

The formation of the Solar System

22 Mercury, Venus, Earth, Mars. 3

3 Jupiter, Saturn, Uranus, Neptune.

The structure of the Earth

4 4 a)a) A – mantle, B – inner core, C – crust, D – outer core. b) b) A – mantle. c) c) B – inner core. d) d) C – crust. e) e) D – outer core. f)

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11 ROCKS AND SOIL

The rock cycle

5 5 a)a) Molten rock made from some of the rocks in the lower crust and upper mantle. b)

b) Basalt and granite.

Types of rock

6 6 a)a)

R

Roocckk IIggnneeoouuss SeSeddiimmeennttaarryy SSmmaalll l ccrryyssttaallss LLaarrgge e ccrryyssttaallss RRoocck k ffrraaggmmeenntts s SShheellllss

sandstone ✔ ✔ granite ✔ ✔ limestone ✔ ✔ basalt ✔ ✔ chalk ✔ ✔ b) b) Metamorphic. c) c) Limestone. d)

d) It is heated and squashed in the Earth’s crust. 7

7D, C, A, B, E

88Crystal shape, colour, luster, hardness and colour of streak. 99 A rock rich in metal compounds.

Soil

10 10 Weathering. 11 11 litter layer bedrock topsoil lumps of bedrock subsoil 12 a)

12 a) Humus, clay particles, sand, stones. b)

b) Clay particles and sand. c)

c) Loam. d)

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12 FINDING THE AGE OF THE EARTH 13 a) 13 a) water soil glass wool measuring cylinder

water that has drained through the soil

b)

b) Same amount of soil; allowed to drain for the same amount of time; same amount of glass wool in funnel. c)

c) A – clay, B – rocky, C – sandy. 14 a) 14 a) 1 2 3 4 5 6 Stations p H 7 8 9 10 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 L L W P H H P C b) b) It increased. c) c) It decreased. d)

d) See graph in answer aa. e)

e) Each plant type grows in a soil of a certain pH. f)

f) Station 9 wild onion; Station 10 lilac.

12

_{Finding the age of the Earth}

How rock layers formed

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12 FINDING THE AGE OF THE EARTH

Naming the rock layers

2

2 Cambrian – Wales – 542; Permian – region in Russia – 300; Devonian – county in England – 416; Cretaceous – chalk rock in Europe – 145; Jurassic – mountains in Switzerland – 200.

3

3 Sedimentary.

How fossils form in rocks

4 4 a)a) It prevents scavengers ripping up the body. b)

b) It reduces oxygen so decomposers cannot thrive and rot the body.

55Minerals. 6 6 a)a) Cambrian. b) b) Quaternary. c) c) Carboniferous. d) d) Jurassic. e) e) Cretaceous.

Fossils and rocks

77Trilobite.

The fossil record

8 8 a)a) Molluscs. b)

b) Examples could include snail, slug, octopus. 9 9 a)a) 0 0 5 5 10 10 N u m b e r o f g r o u p s Time period Time period 15 15 P Pc c C C O O S S D D CCa a P P T T JJ 20 20 b)

b) Silurian and Devonian. c)

c) No, it remained the same in the Ordovician and Silurian periods and in the Carboniferous and Devonian periods.

d) (i)

d) (i) Permian. (ii)

(ii) The number of groups was one lower in the following period, the Triassic. e)

e) As time passes the number of groups increases.

The fossil record and the age of the Earth

10

10 An element whose atoms break down to smaller atoms of other elements and release large amounts of energy.

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13 MEASUREMENTS 11 a) 11 a) 250 g. b) b) 125 g. c)

c) 16 million years old. 12

12 4.6 billion years

13

_Measurements

Fooling our senses

11 Dots appear in the gaps between the squares and seem to move as you move your eyes.

Length, mass and time

2 2 a)a) mm b) b) km c) c) nm d) d) µm e) e) cm

3 3 a)a) Milligram – mg – 0. 000 001; tonne – t – 1000; gram – g – 0.001; kilogram – kg – 1. b) b) Megatonne, Mt. 44 1 2 3 4 5 6 7 8 9 10 T i m e t o f a l l / s e c o n d s Parachute

Time taken for four parachutes to fall three metres

A B

0

D C

This gives the students a chance to produce their own graph, which should be of a size that ﬁlls most of the paper available. Make sure they have labelled the axes and given the chart a title.

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14 FORCES AND MOTION

Accurac

Accuracy of measureme

y of measurements

nts

5

5 From directly in front.

Heat and temperature

6

6 a)a) The hotness or coldness of a substance. b) b) Celsius. c) c) –273 d) d) Alcohol, mercury. e) e) The bulb. f) f) It expands. g) g) It contracts.

14

_{Forces and motion}

Forces and their effects

1 1

Action of a forc

Action of a forcee Action in the gameAction in the game

Changing direction of a moving object C Stopping a moving object D Changing an object’s speed B Changing an object’s shape E Starting an object moving A

Different types of forces – Contact forces

2

2 An impact force. 3

3 Tension. 4

4 a)a) Static friction is stronger than sliding friction. b)

b) Sliding friction. 5

5 a)a)

C

Coonnddiittiioon n oof f rruunnnneerrss PPuulllliinng g ffoorrcce e iin n NN

Rusty 40

Roughly sanded 30 Smoothly sanded 25

waxed 20

b)

b) The rusty runners had rough surfaces but sanding and waxing the surface has made them smooth. c)

c) The frictional force has been reduced. 6

6 a)a) Su Lin. b)

b) Less water will be moved out of the way and the water between the tyre and road will reduce friction.

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15 ENERGY

Different types of forces – Non-contact forces

7 7 a)a) Air resistance. b)

b) It is pulled out of the backpack. c)

c) The skydiver slows down. d)

d) Gravity. 8

8 a)a) Making the objects out of the same mass of material and timing them over the same distance. b)

b) B – It was the most streamlined or had the least water resistance acting on it. c)

c) C – It was least streamlined or had the most water resistance acting upon it. 9

9 The weight is due to the gravitational field strength (pull) of the Earth or the Moon and the gravitational pull of the Moon is only a sixth of the gravitational pull of the Earth.

How springs stretch

10 a) 10 a) 0 0 0 0 22000 0 44000 0 66000 0 80800 0 1100000 0 1122000 0 11440000 Mass/kg Mass/kg E x t e n s i o n / c m 10 10 20 20 30 30 40 40 b)

b) The extension increases in proportion to the increase in mass. c)

c) 1000–1200 kg. d)

d) He could increase the mass to 1000 kg, then increase the mass 50 g at time until the spring no longer extends in proportion.

15

_Energy

What is energy?

11 Energy is a property of something, that can exist in different forms and can make something exert a force or do work.

Forms of energy

2 2 a)a) Chemical energy. b)

b) Gravitational potential energy. c)

c) Strain energy. 3

3 a)a) Chemical energy. b)

b) Gravitational potential energy. c)

c) Strain energy. d)

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15 ENERGY

4 4 a)a)

0 0123456

Distance band pulled back/cm

D i s t a n c e t r a v e l l e d b y b a l l / c m 5 10 15 20 25 30 b)

b) The further the band is pulled back, the further the ball travels. c)

c) The greater the stored energy in the band, the further the ball travelled. Pulling the band back further increases its stored energy.

d)

d) They do not seem to be very accurate as they do not show the pattern clearly. The line is wobbly instead of straight.

e)

e) She could repeat them, taking more care over her measurements. f)

f) The elastic band broke. 5

5It moves. 6

6Solids, liquids and gases.

77Electrical energy is the movement of electrical charges through a conductor. Electromagnetic energy is electrical energy that travels in the form of electromagnetic waves.

8

8Internal energy or thermal energy.

Energy changes

99It changes from electromagnetic energy in light into stored, chemical energy in the food in the leaf. 10

10Heat and sound.

Fuel

11 a) 11 a) D, C, E, B, A b) b) Coal. c)

c) Oil and methane gas. d)

d) Tiny plants and animals that lived and died in the upper waters of ancient seas; dead plankton. 12 a)

12 a) Use the same mass of each fuel, the same mass of water; have the pans the same distance above the fuels; make sure the air is still around both barbecues; hold the thermometer in the same position in both pans when taking the temperature.

(23)

16 ENERGY TRANSFERS b) b) 0 0 10 20 30 40 50 60 70 80 90 100 5 10 Time/min Charcoal Briquettes W a t e r t e m p e r a t u r e / ° C 15 20 25 30 0 0 10 20 30 40 50 60 70 80 90 100 5 10 Time/min W a t e r t e m p e r a t u r e / ° C 15 20 25 30 c)

c) (i)(i) The temperature rises quickly, stays high for a short time then falls quickly. (ii)

(ii) The temperature rises slowly and remains high for longer and starts to cool down more slowly. d)

d) The charcoal releases its energy as heat faster than the briquettes but releases less energy than the briquettes later in the investigation.

16

_{Energy transfers}

Energy transfers and

Energy transfers and transformation

transformationss

1

1 Examples might include beating heart, movement of intestines, blinking of eye, movement of ribs in breathing.

2

2 a)a) (i)(i) 20 joules. (ii) (ii) 60 joules. b) (i) b) (i) 3200 joules. (ii) (ii) 9600 joules. (iii) (iii) 12 800 joules. (iv) (iv) 2 250 000 joules. (v) (v) 2250 kJ.

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16 ENERGY TRANSFERS

How energy use has

How energy use has increased

increased

3 3 a)a) Cars, buses, trains, aeroplanes. b)

b) Oil, candles, wood fires. c)

c) Electricity.

Energy transfer diagrams

4 4 a)a) Stored chemical energy Miguel kinetic energy. Stored chemical energy Miguel thermal energy. b)

b) Stored chemical energy. c)

c) Kinetic energy and thermal energy. d)

d) Miguel. 5 5 a)a) C, A, G, B, E, D, F

b)

b) The more strain energy in the balloon the greater the distance the balloon will travel. c)

c) They match the prediction because the balloon with the greater circumference has the greater strain energy and it travels the greater distance.

6 a) 6 a)and b) b) Energy in fuel 200 kJ Energy in fuel 200 kJ a) Car A a) Car A b) Car B b) Car B Kinetic energy 50 kJ Kinetic energy 100 kJ Waste heat energy 100 kJ Waste heat energy 150 kJ c) c) B

7723% – makes water circulate in the water cycle; 47 % – absorbed by the atmosphere; 0.02 % used by plants in photosynthesis; 30 % reflected back into space; less than 1 % – produces winds and currents.

Plants and energy

88The seed at depth 4 cm used up all its energy trying to grow into the light and did not make it. The other seeds had enough energy to bring them into the light, then they began to photosynthesise and grow.

Energy and ourselves

99The table should have two columns headed ‘Food’ and ‘Energy in 100 g of food in kJ’.

Generating electricity

10 a)

10 a) Kinetic energy of wheel dynamo electrical energy. b)

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17 THE EARTH AND BEYOND

Conservation of energy

11

11 In any energy change some energy is lost as heat. Energy is always conserved.

17

_{The Earth and beyond}

Movements in the sky

1 1 a)a) An imaginary line running through the Earth between the North and South Poles. b)

b) 24 hours._c) c) East.

2 2 a)a) The path of the Earth around the Sun. b)

b) 1 year. c)

c) Yes. We have 365 days in a year and each day and night is the result of a rotation. 3

3 Summer – towards the Sun – winter; Spring – neither towards or away from Sun – autumn; winter – away from the Sun – summer.

4 4 a)a) 146 Ja M Ju Jy S D Month D i s t a n c e f r o m S u n / m i l l i o n s o f k m 147 148 149 150 151 152 153 154 b)

b) It would be a straight horizontal line.

Lights in the sky

55 Light sources – Sun, Arcturus, Milky Way Galaxy, Spica, Andromeda Galaxy. Light reflectors – Moon, Mars, Jupiter, Neptune, Halley’s comet.

Measuring with light

6 6 a)a) 40.85 million million kilometres. b)

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17 THE EARTH AND BEYOND

Bright stars

7 7 a)a) 3 000 – red; 4000 – orange; 6000 – yellow; 11 000 – white; 25 000 – blue b)

b) 6000 °C.

The Moon

88E, C, B, D, A

The parts of the Solar System

99F, D, A, G, C, B, E 10 a)

10 a) Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. b)

b) Mercury. It is nearer the Sun where the Sun’s gravity pulls more strongly on it.

Asteroids

11 a)

11 a) Asteroid belt, Kuiper Belt, Ort Cloud. b)

b) Kuiper belt. c)

c) Ort Cloud.

Planets around other stars

12