SECTION Energy transfers 1 - MR. HUSSAM PHYSICS 1.pdfEnergy transfers take place in many devices. You are going to investigate the energy transfers that take place in some everyday

1SECTION

Energy transfers

© Pearson Education Ltd 2009. Longman 11-14 Physics Practical and Assessment Teacher Pack This document may have been altered from the original

PRACTICAL

Energy transfers take place in many devices. You are going to investigate the energy transfers that take place in some everyday objects.

You may not work through the energy transfers in the order listed below.

Try out each piece of apparatus and answer the questions.

Lamp circuit 1 What happens when you press the switch? 2 What is the source of the energy? 3 What energy transfers are taking place? 4 Draw an energy flow diagram to show the energy transfers. 5 What is the final useful form of energy?

Wind-up electrical item 1 What happens when you wind the handle? 2 What is the source of the energy? 3 What happens when you turn the item on? 4 What is the source of the energy? 5 What energy transfers are taking place when you:

a) wind the handle b) turn on the item?

6 Draw an energy flow diagram to show all the energy transfers. 7 What is the final useful form of energy?

Moving toy 1 What is the source of energy for the toy? 2 What happens to the toy as it is speeding up? 3 What energy transfers take place when the toy moves? 4 Draw an energy flow diagram to show all the energy transfers. 5 What is the final useful form of energy?

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1 Energy transfers


Fan 1 What is the source of energy for the fan? 2 What happens when you switch the fan on? 3 What energy transfers are taking place? 4 Draw an energy flow diagram to show all the energy transfers. 5 What is the final useful form of energy?

Heater 1 What is the source of energy for the heater? 2 What happens when you switch the heater on? 3 What energy transfers are taking place? 4 Draw an energy flow diagram to show all the energy transfers. 5 What is the final useful form of energy?

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1SECTION

Insulation


PRACTICAL

Insulators work by trapping air. You are going to investigate which material makes the best insulator. You will need to think about how you are going to carry out a fair test.

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Safety Clear up any spills.

Apparatus • large beaker

• small beaker

• thermometer

• hot water

• stopclock

• 2 insulating materials

• clingfilm

Method

1 Line the larger beaker with some insulating material. 2 Put the smaller beaker inside the insulating material. 3 Put some hot water and the thermometer in the small beaker. 4 Seal the top of the small beaker with clingfilm. 5 Record the temperature of the hot water. 6 Start the stopclock and record the temperature every minute for 10 minutes.

1 Insulation

© Pearson Education Ltd 2009. Longman 11-14 Physics Practical and Assessment Teacher Pack This document may have been altered from the original Page of 22

Method continued 7 Repeat steps 1–6 with a different insulating material. 8 Remove the insulation from the large beaker and repeat steps 2–6 using just the small

beaker inside the larger beaker with no insulating material.

Recording your results 1 Record your results in a table. 2 Draw a graph to show your results. What type of graph will you use? Explain your

answer.

Considering your results/conclusion 3 Which material was the best insulator? 4 Why did you carry out one test with just the small beaker and no insulation? 5 How did you make sure that you carried out a fair test?

Evaluation 6 How could you improve your investigation if you carried it out again? If there are any

improvements, why would you make them? 7 What do you think this could be a model for?

1SECTION

Solar panels


PRACTICAL

The colour of a solar panel affects how much heat it absorbs from the Sun. You are going to investigate what the best colour is for a solar panel.

Apparatus • 3 foil trays or cans painted different colours • 3 thermometers • stopclock • cold water • lamp

Considering your results/conclusion 3 How did the heat from the lamp reach the water in the trays? 4 Which tray had the biggest rise in temperature?

Safety The foil trays may get hot. Ensure no water splashes on the lamp.

3 Measure and record the temperature of the water in each tray. 4 Record the temperature every 2 minutes for the next 20 minutes.

Method 1 Put some cold water and a thermometer in each foil tray. 2 Place the three trays together and position the lamp over them.

5 Suggest why this tray had the biggest rise in temperature.

Evaluation 6 How did you make sure that you carried out a fair test? 7 What factors that you didn’t control could have affected your experiment? 8 How could you improve your experiment if you carried it out again? Explain your

answer. 9 Do you think trays in any other colours would give better results? Explain your

answer. 10 What conclusions can you draw about the design of solar panels?

Recording your results 1 Record your results in a table. 2 Draw a graph to show your results. What type of graph will you use?

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1SECTION

Specific heat capacity


PRACTICAL

You are going to investigate how quickly different volumes of water heat up when you heat them.

Recording your results 1 Record your results in a table. 2 Plot your results on a graph. What kind of graph are you going to use? Explain your

answer.

Method 1 Put some water in to the beaker. Record the volume of water you used. 2 Place the thermometer and heater in the beaker. 3 Measure and record the temperature of the water. 4 Turn on the heater. At the same time start the stopclock. 5 Measure and record the temperature every minute for 10 minutes. 6 Turn the heater off. 7 Repeat steps 1−6 with fresh cold water and a different volume of water.

Apparatus • 250 cm3 beaker

• thermometer

• low voltage heater

Safety Turn off the heater as soon as you have finished your series of measurements. Do not touch the element part of the heater. Clear up any spills.

• water

• stopclock

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1 Specific heat capacity


6 Explain this difference.

Evaluation 7 What factors could have affected the amount of heat transferred to the water? 8 How could you improve your investigation if you carried it out again? If there are any

improvements, explain why you would make them.

Considering your results/conclusion 3 Describe the shape of each graph. 4 Explain why the graphs have this shape. 5 How is the graph for the second volume of water different from the first?

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1SECTION

Energy transfers

Teacher and technician sheet


PRACTICAL

Safety Ensure that any items of domestic equipment used have been PAT tested and appear on the school’s inventory or are known about by the school’s Health and Safety manager. The heater should be set to get warm, not hot, to the touch. Check the guard on the fan. Note for teacher: Ensure pupils appreciate health and safety considerations for each activity, as they will be handling the equipment. It may be helpful to have a technician to support the class.

Set up this practical as a circus around the laboratory. You may need more than one circus, depending on the number of groups you have.

Resources per circus Notes simple electric circuit with a cell, lamp, press switch and connecting wires

wind-up torch or radio

moving toy This can be battery operated, or mechanical/clockwork.

mains-operated fan

low voltage heater

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1SECTION

PRACTICAL

Insulation



Safety Use water from a hot tap. It is not necessary to use boiling water. Provide cloths to clear up spills.

Resources (per group of pupils) Notes large beaker

There needs to be a sufficient difference in size between the beakers so that there is enough space for the insulating materials between the two beakers. The beakers are acting as a model house.

small beaker thermometer Datalogging equipment could be used. hot water stopclock 2 insulating materials clingfilm

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1SECTION

Solar panels



PRACTICAL

Safety The trays may get hot – pupils will need to take care when touching them after they have been left in front of a light source for a while. Foil trays and cans should have been thoroughly washed before being painted.

Resources (per group of pupils) Notes 3 foil trays or cans painted different colours Use foil trays that takeaway food very

often comes in. For each group, paint one black, one white and leave one unpainted. Alternatively, you can use food cans.

3 thermometers (one for each tray)

stopclock You may want to use 3 stopclocks so that pupils have one for each tray.

cold water

anglepoise (or similar) lamp or infra-red lamp If you are using an anglepoise lamp, you will need to use an incandescent bulb (approx 100 W) – compact fluorescent bulbs do not produce sufficient heat.

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1SECTION




PRACTICAL

Safety Pupils should not touch the element part of the heater. Pupils should turn the heater off as soon as they have finished. Provide cloths to clear up spills.

Resources (per group of pupils) Notes 250 cm3 beaker thermometer low voltage heater A 50 W heater with 200 cm3 of water

should heat tap water to about 55 °C in 10 minutes.

water Discuss with pupils what volumes of water it would be sensible to use.

stopclock

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1SECTION

1.1 Energy transfers


The pictures show many stores of energy and energy transfers.

Questions

1 List the stores of energy in the pictures and the form the energy is stored in. [Total 8]

2 List 10 places where energy transfers are taking place and what the energy transfers are. [Total 10]

3 For each energy transfer you have listed in Q2, draw an energy flow diagram. [Total 10]

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1.2 Energy in the UK


The table compares the amount of energy used in homes in the UK in 1970 and 2006. It takes into account all energy used in the UK – whether it is as electricity, fossil fuels (e.g. gas, oil and coal) or any other form. The quantity used in the table is ‘million tonnes of oil equivalent’. This means that all the forms of energy are expressed as the amount of oil that would be needed to produce the quantity of energy.

Use of energy 1970 2006 space heating 22 26

water heating 10 12

appliances and lighting 2.5 7

cooking 3 2 (Source: Energy Consumption in the United Kingdom, Department of Trade and Industry, 2008)

Questions 1 a) Work out the total amount of energy used in each year. [2]

b) Plot a bar chart of the energy used for each year. [4] [Total 6]

2 a) Work out the percentage of energy used for each category. [4] b) Plot bar charts showing the percentage of energy used in each category for

each year. [4]

[Total 8] 3 a) How has the amount of energy used for each category changed between

1970 and 2006? [1] b) How has the percentage of energy used for each category changed between

1970 and 2006? [1] c) What do you think could have caused these changes? [2]

[Total 4] 4 a) What was the percentage increase in the energy used from 1970 to 2006? [1]

b) In 1970, the population of the UK was 55 632 000. In 2006, the population was 58 886 000. How much of the increase in energy used is due to the increase in population? [2]

[Total 3]

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1SECTION

1.3 Renewables debate


Each speech bubble shows an opinion on what we should be doing to reduce our use of fossil fuels.

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A We should build wind turbines in as many places as possible. It’s a better alternative than seeing land disappear because of rising sea level.

B If we build wind turbines everywhere it will destroy the beautiful views in the countryside. It will also become much noisier in the countryside.

C Wind power is not very reliable – we need other sources. What happens when the wind is not blowing?

D We should install solar panels on the roof of every building in the country.

E We should be building lots more nuclear power stations – it’s the only way we can generate enough electricity to meet the demand for it.

F There’s no point doing anything – it’s already too late to stop sea levels rising. Why should we make life more difficult for ourselves when it won’t have any effect?

G Solar panels are expensive – many people cannot afford them. The Government should subsidise them so that more people can have them.

H Electricity generated by wind turbines is more expensive – I don’t see why I should have to pay more for electricity. It’s already very expensive and prices have gone up a lot!

Questions 1 In a group, discuss each of the opinions in the speech bubbles. a) List the two most important points your group agrees on for each speech

bubble. b) Do you agree with the groups’ agreed list? Explain any differences. 2 Draw your own conclusions on what we should be doing on renewables.

1SECTION

Energy use


HSW

The table shows the use of energy per person in the states of California and Florida over a 28-year period.

Year California Florida 1975 57 54

1980 52 63

1985 50 64

1990 47 69

1995 43 73

2000 43 75

2003 41 77 Energy use per person in gigajoules (1 gigajoule = 109 joules)

(Source: http://www.environmentflorida.org - Global-Warming-Solutions-report, p23)

California has very tough standards for new homes. It also has energy efficiency standards for electrical equipment used in the home.

Questions 1 a) Draw a graph to show the data in the table. Plot both sets of data on the

same axes. [3] b) What trends does your graph show? [2] c) What was the percentage change in energy use between 1975 and 2003 in: i) California ii) Florida? [2] [Total 7] 2 List all the possible technological changes that could have had an impact on energy

usage. [Total 2] 3 The climate in Florida is less extreme than in parts of California, but it is hot in

Florida in the summer. a) What appliances are people more likely to use in the summer in Florida? [1] b) When do you think the highest energy use will be in Florida? [1]

[Total 2] 4 a) What do you think the building standards in California will include? [2] b) Do you think these standards have been successful? Explain your answer. [2]

c) How will the building standards in Florida compare with those in California? [2] d) What recommendations would you make to the state government of Florida

to reduce energy use? [1] [Total 7]

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1SECTION

Prototypes and testing


HSW

Wind turbines are now being used successfully. This has led scientists to think about applying the technology in other areas. The timeline below shows how this technology has developed to date and future proposed developments by one organisation that is involved in developing tidal stream turbines. The organisation started by adapting existing wind turbine technology and using it to design and building a small prototype.

2000 Design small prototype tidal stream turbine by adapting existing technology

2001 Build and test turbine in the laboratory

2002 Improve turbine design

2003 Build prototype turbine and install it off the coast of Devon

2005–7 Design and build bigger turbine

2008 Install turbine in Strangford Lough, Northern Ireland

2008 One of the rotors gets damaged and has to be replaced

2009 Turbine now generating electricity at full capacity

2009 Obtain planning permission for new tidal stream turbines off the coast of Anglesey

2011 Build and install turbines off the coast of Anglesey

Questions 1 Draw a flow chart to show the various stages involved in producing a prototype and

testing it. Don’t forget to include a feedback loop. [Total 4]

2 What problems in building a tidal stream turbine would be similar to those of building a wind turbine? (Hint: think about suitable sites.)

[Total 2] 3 What problems do you think scientists would have had to think about when developing

the first prototype? [Total 2]

4 Find out how the tidal stream turbine in Strangford Lough, Northern Ireland, is maintained.

[Total 2]

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1SECTION

Tidal stream turbines


HSW

The rise and fall of the tides causes tidal currents. Tidal stream turbines are a new way of generating electricity using the energy of a tidal current. One has now been installed in Strangford Lough in Northern Ireland. It is generating electricity which is being supplied to homes. A tidal current changes direction every 6 hours. There is a short time while the tide is changing direction when there is no current. So a tidal stream turbine can generate electricity for 18−20 out of every 24 hours. In many places, the strength of tidal currents is fairly constant. When there is a natural obstruction that the current has to get round, the speed of the current increases around the obstruction. An obstruction could be a headland or somewhere where the channel narrows. Tidal stream turbines need to be built in the middle of the strongest tidal stream. The speed of tidal currents is much less than the speed of the wind. This is because water is much denser than air. 1 m3 of air has a mass of about 1.25 kg whereas 1 m3 of sea water has a mass of over 1000 kg. The amount of energy a moving object has is related to its mass, so 1 m3 of moving sea water has much more energy than 1 m3 of air moving at the same speed. Many ships and boats travel through the potential sites for the turbines. Tidal barrages also make use of the tides. Instead of making use of the tidal streams, they make use of the difference in the sea level between high tide and low tide. A tidal barrage involves building a dam across an estuary to hold the sea water in a reservoir. It operates more like a hydroelectric power station – it can only operate when there is a difference between the level of water on either side of the turbine. When the tide is falling, you have to wait until the tide has fallen enough so that the height difference is sufficient. This means that it can only generate electricity for 4−6 hours out of every 24 hours. Tidal barrages can change the ecosystem of an estuary.

Questions 1 a) What advantages do tidal stream turbines have over wind turbines? [2]

b) What disadvantages do tidal stream turbines have over wind turbines? [2] [Total 4]

2 a) What advantages do tidal stream turbines have over tidal barrages? [2] b) What disadvantages do tidal stream turbines have over tidal barrages? [2]

[Total 4] 3 a) What causes tidal currents? [1]

b) What natural features could cause an obstruction that will increase the size of the tidal current? [1]

[Total 2]

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1 Tidal stream turbines


Questions continued 4 What would be the ideal site for a tidal stream turbine?

[Total 2] 5 The energy density of water is much higher than that of the air. What do you think this

means? [Total 1]

6 Name one similarity and one difference between tidal stream turbines and tidal barrages.

[Total 2]

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1SECTION

U-values and buildings


EXTENSION

All parts of a building have a U-value. The U-value is a measure of how much energy a material conducts, per unit of area. The lower the U-value, the less energy the material conducts, and the better insulator it is. Building Regulations in England specify what the maximum U-value of certain parts of a house can be. The maximum U-value allowed has been reduced over the past 40 years. The maximum U-values allowed by English Building Regulations are shown in the table. (The units are joules per second per square metre per degree Celsius of temperature difference between the inside and the outside of the house.)

Part of building 1965 1976 1985 1990 2002 walls 1.7 1.0 0.6 0.45 0.35

roof 1.0 0.6 0.35 0.25 0.16−0.25* *Depends on type of roof.

Many older houses have solid walls. Newer houses have cavity walls. Cavity walls have two layers of brick – an inner layer and an outer layer with a cavity in-between them. The cavity is filled with air. This method of construction became widespread in the 1920s. Cavity walls transfer much less heat than a solid wall. Cavities are now filled with insulating materials such as cellulose insulation or rock wool to reduce the amount of heat transferred by the wall. The minimum recommended amount of roof insulation increased from 25 mm in the 1960s to 270 mm in 2003.

Questions 1 a) Why do you think the Building Regulations have reduced the maximum

U-value allowed? [1] b) What effect do you think this has had on houses? [2]

[Total 4] 2 Will a solid wall have a higher or lower U-value than a cavity wall? Explain your answer.

[Total 2] 3 Why is it important to have walls and a roof with a low U-value in a building with air-

conditioning? [Total 1]

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1 U-values and buildings


Questions continued 4 a) How is heat transferred through a solid wall? Explain your answer using the

particle theory. [2] b) How is heat transferred through a cavity wall? [3] c) How does the insulation in a cavity reduce the amount of heat that is

transferred across the cavity? [2] [Total 7]

5 a) How is heat transferred through a single glazed window? [2] b) How do you think double glazing reduces the amount of heat transferred? [2] c) Why do you think triple glazing is used in countries like Sweden? [1]

[Total 5] 6 Research what has happened to Building Regulations since 2002. (Hint: the regulations

do not now consider just U-values but take other factors into account.) [Total 2]

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1SECTION

EXTENSION

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Coastal breezes


The second diagram shows what happens on a hot summer day.

The diagram below shows the position of two boats in relation to the coast. A light breeze is blowing from the west along the coast. It is a sunny day in the middle of summer.

Questions 1 a) What happens as the land heats up? (use the diagram above to help you.) [2]

b) What effect will this have on the direction of the wind close to the land as the oes on? (Hint: think of what happens to the temperature of the land

tal 4] 2 a)

b) What effect will this have on the direction of the wind close to land? [Total 3]

day gduring the day.) [2]

[ToWhat will happen after sunset to the relative temperatures of the land andsea? [2]

[1]

Coastal breezes


A sailing boat cannot sail in the area 45 degrees either side of the wind. The closest a boat can sail to the wind is 45 degrees to the wind. If a sailing boat wants to go in the direction the wind is coming from, it first has to sail in one direction at 45 degrees to the wind (like the boat on the right of the diagram below) and then change direction (or tack) by 90 degrees so that it is at 45 degrees to the wind in the direction shown by the middle boat in the diagram

below. It will keep on doing this until it gets to its destination.

Questions boat wants to sail from Easthampton to Little Snoring on Sea, taking the

[Total 2] 4 Two boats are racing from Easthampton to Little Snoring on Sea. They set off

wind have on the tracks that the two boats can take? [4]

[Tota

3 A sailing shortest possible route sailing. Should it start sailing in the morning or afternoon? Explain your answer.

in the afternoon. Boat A decides to stay close to the shore. Boat B decides to stay much further offshore. a) What effect will the b) Which boat will get to Little Snoring on Sea quicker? Explain your answer [1]

l 5]

1SECTION

Questions and answers


How is energy transferred in a liquid? By convection How is energy transferred from the

Sun? By radiation

How is energy transferred in a metal? By conduction What is the source of most energy

on the Earth? The Sun

A light bulb uses 12 W and produces 6 W of light energy. What is its efficiency?

50% What kind of energy does a stretched spring contain? Elastic potential

What energy transfer takes place in a gas cooker?

Chemical energy to heat and light energy

What name is given to the amount of heat needed to heat 1 kg of a substance by 1 °C?


What type of diagram can you use to show energy transfers?

Energy flow diagram or Sankey diagram

What happens to the particles in a solid when you cool the solid down?

They vibrate more slowly.

Is nuclear energy a renewable resource or a non-renewable resource?

Non-renewable How is heat transferred around a room?

By a convection current

What method of energy transfer happens in liquids and gases? Convection What is the hot air rising above the

land called? A thermal

What is a non-renewable energy resource?

A resource that will run out

What is the process of heat transfer from the surface of a liquid called? Evaporation

What is a renewable energy resource?

A resource that will not run out

What method of heat transfer cools the body when you sweat? Evaporation

What is the original source of the energy in the waves? The Sun Name three fossil fuels. Coal, gas, oil

What is the name of the device that can convert light energy directly to electricity?

Photocell What effect do carbon dioxide emissions contribute to?

Greenhouse effect

What do solar panels do? Heat water using energy from the Sun

Does nuclear power contribute to global warming? No

What is the name of a substance that reduces heat loss? An insulator What is methane that is produced

from rotting food called? Biogas

What kind of energy does water have when it is held in a dam for a hydroelectric power station?

Gravitational potential energy

What kind of energy does moving water have? Kinetic energy

What is a solid called that allows heat to travel through it quickly? A conductor

What is the process called where energy is transferred through a substance by the vibrations of particles?

Thermal conduction

PROGRESSION1

SECTION

Energy

Name Date Class


Tick the boxes that apply. Or use traffic lights to show how confident you are (red = ‘I don’t know this’; orange = ‘I’m not very confident about this’; green = ‘I’m confident I know this’).

Level At the end of the section I can do this

I need more work on this

5 Describe what energy is and state the units it is measured in.

5 List the different forms of energy.

5 Explain the law of conservation of energy.

5 Explain what heat is and state its unit.

5 Explain what the temperature of an object is and state the units it can be measured in.

6 Explain where most of the Earth’s energy comes from.

6 Describe the four main methods of energy transfer.

6 List and explain the four main methods of heat transfer in solids, liquids and gases.

6 Using examples explain three methods of reducing the rate of thermal energy transfer.

6 Describe the main features of the two main groups of energy resources.

6 Name and describe the different energy resources.

6 Represent energy transfers using Sankey diagrams.

7 Explain how we can use energy resources more efficiently.

7 Explain how we can reduce the usage of fossil fuels.

7 Explain how thermal energy is transferred across the vacuum between the Sun and the Earth.

7 Use the particle theory to explain how a puddle of water dries by evaporation.

7 Explain what the greenhouse effect is.

7 Explain what radioactivity is.

7 Describe some of the uses of radioactivity.

8 Explain how methods of heat transfer can cause winds during the day and night.

1 Energy




8 Discuss the efficiency of appliances using the law of conservation of energy.

EP Describe some of the difficulties in meeting the demand for electricity.

PROGRESSION1

SECTION

Energy

Name Date Class


Tick the boxes that apply. Or use traffic lights to show how confident you are (red = ‘I don’t know this’; orange = ‘I’m not very confident about this’; green = ‘I’m confident I know this’).



Describe what energy is and state the units it is measured in.

List the different forms of energy.

Explain the law of conservation of energy.

Explain what heat is and state its unit.

Explain what the temperature of an object is and state the units it can be measured in.

Explain where most of the Earth’s energy comes from.

Describe the four main methods of energy transfer.

List and explain the four main methods of heat transfer in solids, liquids and gases.

Using examples explain three methods of reducing the rate of thermal energy transfer.

Describe the main features of the two main groups of energy resources.

Name and describe the different energy resources.

Represent energy transfers using Sankey diagrams.

Explain how we can use energy resources more efficiently.

Explain how we can reduce the usage of fossil fuels.

Explain how thermal energy is transferred across the vacuum between the Sun and the Earth.

Use the particle theory to explain how a puddle of water dries by evaporation.

Explain what the greenhouse effect is.

Explain what radioactivity is.

Describe some of the uses of radioactivity.

Explain how methods of heat transfer can cause winds during the day and night.

1 Energy




Discuss the efficiency of appliances using the law of conservation of energy.

Describe some of the difficulties in meeting the demand for electricity.

1SECTION

End of section test

Name

H I G H E R

Date Class


1 a) Why is solar power called a renewable energy resource? ________________________________________________________________ ________________________________________________________________ [1]

b) Why should we be using more renewable energy resources? ________________________________________________________________ ________________________________________________________________ [1]

[Total 2] 2 What form of heat transfer is shown in each picture?

a) ________________________ b) ________________________

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[Total 2] 3 A wind-up torch stores energy in a spring when you wind the handle. This stored energy

is then used to light the bulb. a) What form of energy is stored in the spring?

________________________________________________________________ [1] b) Draw a flow diagram to show the energy transfers that take place in the torch. [3] c) Sam says that some of the energy disappears when it is transferred. Is he right

or wrong? Explain your answer. ________________________________________________________________ ________________________________________________________________ [1]

[Total 5]

1 End of section test


4 Rachel carried out an experiment where she wrapped two different materials round a beakers of hot water. She measured the temperature of each beaker every minute for 10 minutes. She also measured the temperature of a beaker of hot water with nothing wrapped around it. The graph shows her results.

a) Why did Rachel measure the temperature of a beaker with nothing wrapped around it? _______________________________________________________ [1]

b) Which line on the graph shows the results for nothing wrapped round the beaker? Explain your answer. _______________________________________

________________________________________________________________ [2] c) Which line on the graph shows the best insulating material? Explain your

answer. ________________________________________________________ ________________________________________________________________ [2] d) Some of Rachel’s readings do not look correct? Which ones are they? ________________________________________________________________ [1] e) What may have happened while Rachel was carrying out her experiment that

would account for these results? Give two reasons. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

[Total 8]

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5 A light bulb is supplied with 20 J of energy. 9 J is transferred to light energy. a) What is the remaining energy transferred to? ____________________________ [1] b) Draw a Sankey diagram for the light bulb. [2] c) What is the efficiency of the light bulb? ________________________________ [1]

[Total 4] 6 Drawing pins are stuck to a metal bar with wax. The end of the bar is heated as shown in

the diagram.

a) What will happen to the pins and in what order? _________________________ ________________________________________________________________ ________________________________________________________________ [1] b) Explain why this will happen. Use the word ‘particle’ in your answer. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2] c) What is the name of the process of heat transfer? ________________________ [1]

[Total 4]

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1SECTION

End of section test

Name

EXTENSION

Date Class


1 A light bulb is supplied with 20 J of energy. 9 J is transferred to light energy. a) What is the remaining energy transferred to? ___________________________ [1] b) Draw a Sankey diagram for the light bulb. [2] c) What is the efficiency of the light bulb? ________________________________ ________________________________________________________________ [1]

[Total 4] 2 Drawing pins are stuck to a metal bar with wax. The end of the bar is heated as shown in

the diagram.

a) What will happen to the pins and in what order? _________________________ ________________________________________________________________ ________________________________________________________________ [1] b) Explain why this will happen. Use the word ‘particle’ in your answer. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

[Total 3]

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3 Ryan is playing tennis on a hot day. Explain how sweating helps to cool his body down. ________________________ _________________________________________________________________ _________________________________________________________________

[Total 3] 4 The diagram shows heat being transferred

from the heating element of a kettle to the water inside it.

a) What is the name of the heat transfer process? _________________________ [1] b) Explain what is happening at points A, B and D. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [3] c) Heat passes through the side of the kettle.

Why is it not the same process as in part a)? ________________________________________________________________ ________________________________________________________________ [2] d) How is thermal energy transferred across a vacuum? ____________________ [1]

[Total 7] 5 a) Explain what the greenhouse effect is and why it is happening. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ [2]

b) How is our use of fossil fuels contributing to the greenhouse effect? _________________________________________________________________ [1]

c) Give two things we can do to reduce our use of fossil fuels. _________________________________________________________________ _________________________________________________________________ [2]

[Total 5]

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6 A hotel in the Isles of Scilly wants to use more renewable energy. There is a reasonable amount of wind and it is quite sunny. a) What type of renewable energy could the hotel use? Explain your answer. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2] b) Give one disadvantage of the type of renewable energy you have given in

part a). _________________________________________________________ ________________________________________________________________ ________________________________________________________________ [1] c) The hotel owner is thinking about using more efficient appliances in the hotel.

Explain how this could reduce the total amount of energy used in the hotel. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ [2]

[Total 5]

1SECTION

End of section mark scheme


Higher tier (equivalent to NC levels 5 and 6)

Question Answer Mark scheme NC Level (optional)

1 a because it will not run out (until the Sun eventually dies)

1 mark 5

b because they do not contribute to global warming

1 mark 5

2 a convection 1 mark 5

b radiation 1 mark 5

3 a strain or elastic potential energy 1 mark 6

b kinetic energy elastic potential energy electrical energy light energy + heat

energy

3 marks: all stages correct 2 marks: 3 stages correct 1 mark: 2 stages correct

6

c He is wrong, because energy cannot be created or destroyed.

1 mark 5

4 a so that she had a control 1 mark 6

b line C because the temperature of the water dropped the most

1 mark 1 mark

6

c line A because the temperature of the water dropped the least

1 mark 1 mark

6

d the ones at 2 minutes and 6 minutes on line C

1 mark 6

e misread the temperature on the thermometer misread the time or other suitable explanations

1 mark 1 mark

6

5 a heat energy 1 mark 6

1 End of section mark scheme


b

2 marks 6

c 45% 1 mark 6

6 a The pins will fall off one after another starting with the one closest to the heat.

1 mark 6

b The particles over the heat vibrate faster and collide with other particles next to them.

1 mark 1 mark

6

c conduction 1 mark 5

Extension tier (equivalent to NC levels 6, 7 and 8)


1 a heat energy 1 mark 6

b

2 marks 6

c 45% 1 mark 6

2 a The pins will fall off one after another starting with the one closest to the heat.

1 mark 6

b The particles over the heat vibrate faster and collide with other particles next to them.

1 mark 1 mark

6

3 The water particles in his sweat escape into the air. The evaporating water particles take energy with them. This reduces the temperature of the skin.

1 mark 1 mark 1 mark

7

4 a convection 1 mark 5

b A: The water is displaced by the rising warmer water.

1 mark for each correct answer

7

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1 End of section mark scheme


B: The cooler water sinks. D: The water passes over the heater and gains energy.

c Particles in a solid cannot move so a convection current cannot form.

1 mark 1 mark

7

d radiation 1 mark 7

5 a Heat is trapped in the Earth’s atmosphere by carbon dioxide and other greenhouse gases. We are adding carbon dioxide to the atmosphere

1 mark 1 mark

7

b It produces carbon dioxide which is added to the atmosphere.

1 mark 7

c two of: insulating homes, lowering central heating thermostat, walking or cycling for short journeys, using more fuel-efficient cars, using electricity from renewable sources

1 mark for two correct – accept equivalent answers

7

6 a one of solar panels, photocells or wind turbines to generate electricity/heat water because both of the resources are available

1 mark for energy resource and 1 mark for an explanation

7

b Wind doesn’t always blow/photocells and solar panels don’t work at night.

1 mark 7

c A higher proportion of the energy is transferred into useful energy than into wasted energy. This means less energy is required overall.

1 mark 1 mark

8

1SECTION

Question bank

Name Date Class


1 What energy transfer process does the diagram show? ___________________________________________

[Total 1] 2 The diagrams show energy transfers. For each diagram:

i) list the energy transfers taking place ii) draw an energy flow diagram.

a) i) ________________________________ [1] ii)

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[1] b) i) ________________________________ [1] ii) [1] c) i) ________________________________ [1] ii) [1]

[Total 6] 3 The diagram shows an ice lolly. Explain what happens

to the air near the ice lolly. __________________________________________ __________________________________________ __________________________________________ __________________________________________

[Total 3]

1 Question bank


4 The diagram shows some heat transfers taking place. Explain how the heat energy gets from the flame to the vegetables in the pan. Include all

the heat transfers.

Cooking vegetables. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

[Total 3] 5 The diagram shows some heat transfers taking place.

Explain how the heat energy gets from the heating element to you, when you are sitting on the other side of the room to the heater.

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Heater. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

[Total 3] 6 Solar, wind, hydroelectric and geothermal are all examples of renewable energy

resources. Choose one of these resources and give one advantage and one disadvantage. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

[Total 2]

1 Question bank


7 Mina has just received her winter fuel bill. She is shocked by how big the bill is. Give two things that Mina could do to reduce her fuel bill. ___________________________________________________________________ ___________________________________________________________________

[Total 2] 8 For every 100 J of energy that is supplied to a car engine, only 23 J is useful energy.

a) What form is the useful energy in? ____________________________________ [1] b) Ryan says that the rest of the energy disappears. Explain why Ryan is wrong. ________________________________________________________________ ________________________________________________________________ [2] c) What form is the rest of the energy in? _________________________________ [1] d) Work out the efficiency of the car engine. _______________________________ ________________________________________________________________ [1]

[Total 5]

1SECTION

Question bank mark scheme



1 convection 1 mark 5

2 a i kinetic energy in air to sound and heat energy in surroundings

1 mark 6

ii kinetic energy → sound energy + heat energy

1 mark 6

b i elastic potential (strain) energy in catapult to kinetic energy in stone and heat energy in surroundings

1 mark 6

ii strain energy → kinetic energy + heat energy

1 mark 6

c i electrical energy to light energy, sound and heat energy from TV

1 mark 6

ii electrical energy → light energy + sound energy + heat energy

1 mark 6

3 The air by the ice lolly cools down. As cooler air is denser, it falls. Air comes from above to replace it.


6

4 Heat goes through the metal pan by conduction. Heat spreads through the liquid in the pan by convection. Heat is transferred to the vegetables from the liquid by conduction.


6

5 Heat energy is transferred from the element to the air by conduction. The air rises and it is pushed out of the way by more warm air rising beneath it. A convection current is formed, which spreads the heat around the room.


6

6 Pupil chooses one resource and gives an advantage and a disadvantage of the chosen resource.

2 marks – 1 mark for each correct advantage or disadvantage

7

7 Any two of the following, or equivalent answers: switch off electrical equipment when it is not in use; do not leave electrical equipment on standby; use low-energy

2 marks – 1 for each point

7

1 Question bank mark scheme


light bulbs; use a jug-type kettle with only the amount of water you need; use a toaster instead of a grill; use a microwave oven instead of a conventional oven; set the central heating thermostat lower; wear more clothes at home.

8 a kinetic 1 mark 5

b The law of conservation of energy says that energy cannot be created or destroyed.

2 marks – 1 mark for use of the term law of conservation of energy, 1 mark for stating what that law is

8

c heat energy and sound energy 1 mark – both must be given

5

d 23% 1 mark 8

1SECTION

Answers


Pupil Book answers 1.1 Introduction to energy – Quick check questions 1 potential energy [1] kinetic energy [1]

sound energy [1] + thermal energy [1] [4]

2 30% [1]

1.1 Introduction to energy – Questions 1 Energy is the ability to do work. Energy cannot

be created or destroyed, it can only be transferred from one form to another. [1 x 4] [4]

2 joule, kilojoule [2]

3 a) chemical thermal (heat) and light [2]

b) kinetic (movement) sound [2]

c) electrical thermal and light [2]

d) chemical thermal kinetic (movement) [2]

4 A lamp transfers electrical energy to thermal energy and light energy. A radio transfers electrical energy to sound energy. Exploding dynamite transfers chemical energy to heat, light, sound and kinetic energy. A falling apple transfers gravitational potential energy to kinetic energy. [4]

5 list of six energy transfers in the picture [6]

6 a) chemical thermal light [3]

b) electrical kinetic sound [3]

c) kinetic sound [2]

d) electrical thermal [2]

e) chemical thermal kinetic sound [4]

f) nuclear thermal kinetic electrical [4]

7 a) As the toy bounces, energy is transferred between potential and kinetic energy and back again. [1]

b) Friction between the moving toy and the air [1] causes some energy to be transferred to thermal energy [1]. Eventually all the kinetic/potential energy that the toy originally had is

eventually transferred to thermal energy [1]. [3]

c) i) elastic [1] and gravitational [1]. [2]

ii) gravitational at the top of each bounce [1], and elastic when the spring is stretched at the bottom of each bounce [1]. [4]

8 a) correct Sankey diagram [5]

b) 25% [1], as only 25% of the energy stored in the petrol is transferred to a useful form of energy [1]. [1]

1.2 Thermal energy – Quick check questions 1 a) 5 x 390 J = 1950 J [1]

b) 2 x 910 J = 1820 J [1]

2 It is a solid [1], so vibrations can be passed from particle to particle easily [1]. It is a metal [1], so electrons can also transfer thermal energy [1]. [4]

3 The sketch should show cold air currents moving down next to the lolly. [1]

4 The bubbles you see in boiling water are steam (i.e. water as a gas), not air [1]. When a puddle evaporates, water molecules escape from the surface. Bubbles of steam do not form inside the water [1]. [2]

5 The earth-covered roof, earth bank, and wooden walls are all good insulators, and reduce the amount of thermal energy transferred through the roof and walls [1]. The small size of the windows and the double glazing reduce the heat transferred through the windows [1]. If less heat is lost, then less energy is needed to heat the house [1]. The conservatory absorbs heat, which means less energy is needed for central heating [1]. [4]

1.2 Thermal energy – Questions 1 Heat can be transferred by conduction,

convection, radiation and evaporation. A good thermal conductor is a substance through which heat travels quickly. An insulator does not let heat flow through it well. When heat is transferred by convection, hotter regions rise. Thermal energy travels from the Sun to the Earth by radiation. Wet skin will dry quicker by evaporation on a hot, windy day. [½ x 10] [5]

2 a) ii) (Collisions between…) [1]

1 Answers


b) iv) (Hot fluids rise…) [1]

c) i) (The transfer of thermal…) [1]

d) iii) (Higher energy molecules…) [1]

3 conductors: copper, aluminium, iron, tin [4] insulators: feathers, polythene, fur, wood [4]

4 Cooled air will fall [1] creating a convection current [1] cooling all parts of the room/reducing temperature gradients [1]. [3]

5 a) convection [1]

b) Any three from: • fitting draught excluders to doors • fitting draught excluders to windows • fitting draught excluders to letterboxes • using heavy curtains (or other correct answers) [3]

6 a) cost of installation bar chart [4] annual saving for each method bar chart [4] [8]

b) double-glazing [1]

c) double-glazing [1]

d) about 9 years [1]

e) fitting jacket to hot water tank [1]

7 Four different correct key points, e.g. Heat is a form of energy. Temperature is a measure of how hot something is. Heat is measured in joules. Temperature is measured in degrees Celsius. [4]

8 a) 60 [1] °C [1] [2]

b) 4 × 84 = [1] 336 [1] kJ [1] [3]

c) E – 0.25E = 336 [1] 4/3 x 336 = [1] 448 [1] kJ [1] [4]

1.3 Energy resources – Quick check questions 1 No carbon dioxide is released. [1]

2 The weather is better/the Sun shines more often in Greece and Spain than in the UK. [1]

3 The wind does not blow all the time, so there would be times without electricity [1]. We would need to cover a lot of land in wind farms to generate enough electricity [1]. [1]

4 burnt to heat homes or cook food [1], fermented to produce methane to use as a fuel [1], fermented to produce alcohol to use as a fuel [1], burnt to produce electricity [1] [4]

5 Insulation – if less heat escapes from homes, we do not need to burn as much fossil fuel to keep them warm [1]. Thermostat – we will burn less fuel if the house does not have to be as warm [1]. Walking/cycling – this avoids burning petrol in cars or buses [1]. Cars – a more fuel-efficient car will burn less petrol for a given journey [1]. Electricity generated using renewable resources does not burn fossil fuels [1]. [5]

1.3 Energy resources – Questions 1 Fossil fuels are non-renewable energy

resources. Solar power and biomass are examples of renewable energy resources. We need to reduce/limit/control our use of energy to help reduce the emission of greenhouse gases and conserve the world’s energy resources. [½ x 6] [3]

2 a) Renewable energy resources can be replaced in our lifetime. Non-renewable resources take millions of years to replace. [2]

b) Three examples of renewable energy resources: wind, solar, tidal, biomass, hydroelectric, geothermal [3] Three examples of non-renewable energy resources: coal, oil, gas, nuclear [3] [6]

3 a) Coal is formed from plant and animal matter. These plants and animals would not have existed without energy from the Sun. [2]

b) The Sun warms the air creating the convection currents that cause wind [2]

c) Waves are generated by the wind. Winds are formed from the Sun’s energy. [2]

4 Possible answers:

Resource Advantages Disadvantages Solar No fuel costs.

Does not produce carbon dioxide.

Can be used for heating or for

Only available in the daytime in good weather.

Solar cells are expensive.

1 Answers


Resource Advantages Disadvantages generating electricity.

Wind No fuel costs.


Only available when it is windy.

Wind turbines spoil the view and may kill birds.

Waves No fuel costs.


Only available when there are large waves.

Needs large areas of sea to be covered with generators.

Tidal No fuel costs.


Available at predictable times.

Expensive barrage or turbines need to be built.

Barrages may affect wildlife.

[for each energy source, 1 mark for correct entries in both Advantages and Disadvantages columns] [4]

5 The hotel probably used solar panels to heat the water. Once the hot water had been used the Sun would not heat any more until the next day. [2]

6 a) three suitable renewable energy resources, e.g. wind generators, biomass (wood), solar cells, (wave, tidal, solar panels, geothermal would not be suitable in the circumstances) [3]

b) 2 marks for each energy source suggested, with an explanation of as to how their energy need would be met, and how it would be a practical energy resource for them [6]

HSW – The greenhouse effect– Quick check questions 1 ground, glass, air [3]

2 carbon dioxide, water vapour, methane [3]

HSW – The greenhouse effect – Questions 1 a) the glass [1]

b) The glass in a greenhouse stops some of the thermal energy escaping from the air in the greenhouse [1], and greenhouse gases stop some of the thermal energy radiated by the Earth escaping into space [1]. [2]

c) The glass mostly prevents heat escaping from a greenhouse by preventing convection currents [1], whereas greenhouse gases absorb the radiation, so this part of the model is not very accurate [1]. [2]

d) pupil’s own answer [1]

2 a) evaporation from the oceans [1]

b) We cannot control the amount of water that evaporates. [1]

3 Domestic cows emit methane from their digestive system [1], so if we did not farm as many cows for meat, there would be less methane put into the atmosphere [1]. [2]

HSW – Meeting the demand – Quick check questions 1 a) coal, oil, gas [3]

b) nuclear [1]

2 because electricity cannot be stored [1]

3 Non-renewable resources will run out one day. Carbon dioxide is put into the air when fossil fuels burn, and this is causing global warming. [2]

HSW – Meeting the demand – Questions 1 a) The days are shorter, so we need

more energy for lighting [1]. The weather is colder, so we need more energy for heating [1]. [2]

b) i) around 6 pm/18.00 [1]

ii) people are cooking their evening meals, and have the heating on in their houses [1]

2 a) tidal [1], wind [1], waves [1], solar [1] [4]

b) wind [1] and waves [1], as windy weather is more common in the winter [1] [3]

3 a) If we used biomass crops, we would use less fossil fuels/put less carbon dioxide into the atmosphere. [1]

b) Clearing land for growing crops would destroy habitats. [1]

1 Answers


c) People may gain employment/make money from growing the crops [1], but if crops are grown instead of food, food prices would go up [1] and some people may not be able to buy enough food to survive [1]. [3]

4 a) tidal [1] and waves [1], as Austria has no coastline/is not next to the sea [1] [3]

b) solar [1]; Spain is further south, and is more likely to be sunny (or the sun is stronger there) [1]. [2]

HSW – Using radioactivity – Quick check questions 1 They made careful measurements of the

amount of radiation emitted by uranium ore [1] and found that this was more than could be explained by the uranium in them [1]. [2]

HSW – Using radioactivity – Questions 1 a) lead [1]

b) Marie Curie's notebooks are kept in lead-lined boxes [1], so the lead must help to stop the radiation getting out [1]. [2]

2 a) The chemical would have to be tested [1] to make sure it had no harmful effects on people [1]. [2]

b) In the 1900s there did not appear to have been any testing for safety [1]. If there had been, radioactive materials would not have been used in so many different items [1]. Also, there did not appear to have been any testing to find out if the radioactive materials did have any of the benefits advertised [1]. [3]

3 Radioactivity can make a piece of photographic film go dark [1]. The film is kept in a special holder that stops light from affecting the film, but allows radioactivity to go through it [1]. This is worn on the clothing of people who work with radioactivity [1]. Every few months the film is removed and replaced with a new piece of film [1.] The film from the badge is developed, and the amount of darkening will show how much radiation the wearer was exposed to [1]. [4]

End of section questions 1 (1 mark for each device and correct principle

energy transfer), e.g. kettle: electrical to thermal television: electrical to light and sound torch: chemical to light gas cooker: chemical to thermal portable radio: chemical to sound [5]

2 a) petrol: fossil, chemical [2] engine: thermal, kinetic, sound [2] friction: kinetic, thermal, sound [3]

b) chemical heat kinetic gravitational potential [4]

3 Energy cannot be created or destroyed It can only be transferred from one form to another. [2]

4 kinetic energy: 40J [1] thermal energy: 150 J [1] sound energy: 10 J [1] [3]

5 1000 000/500 = [1] 2000 [1] metres [1] [3]

6 a) The temperature of the horseshoe would decrease [1]. The temperature of the water would increase [1]. [2]

b) Thermal energy has been transferred from the horseshoe to the water. [2]

7 a) Conduction is the principal method of in solids [1]. Increasing the temperature causes molecules to vibrate faster [1]. Thermal energy is transferred from one molecule to another [1]. [3]

b) Convection is the principal method in liquids and gases [1]. As the fluid is heated it expands[1]. The hot fluid rises through the colder fluid around it [1]. [3]

c) Transfer of thermal energy by an electromagnetic wave [1]. Can travel through a vacuum [1]. Black surfaces are good absorbers and emitters of thermal radiation [1]. [3]

8 The air inside the fridge is cold [1]. Cold air is denser than warmer air [1], so it sinks through the warmer air in the kitchen [1] [5]

1 Answers


9 When water is boiling the change of state occurs throughout the liquid as molecules gain enough energy to move further apart [2]. Evaporation is a surface effect, so only those molecules with sufficient energy escape from the surface and form a vapour [2]. [4]

10 a) axes drawn with appropriate scales [1] both axes labelled including units [1] first set of data correctly plotted [1] second set of data correctly plotted [1] best fit curves drawn for both sets of data [2] [6]

b) For both cups the temperature decreased with time but the paper cup without a lid cooled faster showing it lost thermal energy at a faster rate. [3]

c) It was not a fair test because the starting temperatures were different. OR because one cup had a lid and one didn’t. She could let each cool to 80 °C before starting to time them OR she should choose with/without lid. [3]

11 a) North America [1]

b) North America [1]

c) The Middle East does not have sufficient rain and also has a good supply of oil and gas. [2]

d) bar chart [6]

e) oil, gas and coal [1], as they all release carbon dioxide when they burn [1] [2]

12 a) light energy electrical energy chemical energy [2]

b) electrical energy kinetic energy + sound energy + thermal energy [4]

Practical and Assessment Teacher Pack answers Topic worksheets 1.1 Energy transfers 1 pupil’s own answers, but could include: petrol

– chemical energy; food – chemical energy [8]

2 pupil’s own answers, but could include: car – chemical energy to heat energy to kinetic energy and sound energy [1 for each place with correct transfers] [10]

3 pupil’s own answers, e.g. chemical energy thermal energy kinetic energy + sound energy [1 for each energy transfer] [10]

1.2 Energy in the UK 1 a) 1970: 37.5 mtoe; 2006: 47 mtoe [2]

b) marks should be awarded for labelled axes, correct scales, correctly plotted bars, units given on axis

2 a) [4]

Use of energy 1970 2006

space heating 58.7% 55.3%

water heating 26.7% 25.5%

appliances and lighting 6.7% 14.9%

cooking 8.0% 4.3% (Numbers have been rounded.)

b) suitable bar charts [4]

3 a) all increased except cooking [1]

b) all decreased except appliances and lighting [1]

c) increased use of appliances like TVs – homes did not have PCs in the 1970s, people cooking less at home – using more ready-made meals/eating out [2]

4 a) 26.7% [1]

b) population increased by 5.8%; 2.2 mtoe [2]

HSW worksheets Energy use 1 a) marks awarded for line graph drawn,

correctly plotted points, labelled axes [3]

b) Energy use per person has decreased in California and increased in Florida [2]

c) i) 28% decrease [1]

ii) 43% increase [1]

2 Varied answers, could include: increasing use of computers, more appliances in houses, more TVs, bigger houses, more air conditioning/heating [2]

1 Answers


3 a) air conditioning [1]

b) in the summer [1]

4 a) sensible suggestions including high levels of insulation, double glazing, encouraging use of more efficient appliances [2]

b) yes, because energy usage per head has dropped even with all the extra appliances [2]

c) They will be much lower – energy use per head has increased in Florida. [2]

d) to adopt similar standards for building and appliances as those in force in California [1]

Prototypes and testing 1 pupil’s own flowchart; should include

feedback loop for improving the design [4]

2 suitable sites for turbines and access to them; wind turbines are often built in inaccessible places – access to tidal power turbines is also difficult [2]

3 Turbine will be underwater and so much more difficult to maintain. Environment is extremely harsh – sea water is very corrosive. [2]

4 Pupil’s own answer but should include that turbine can be lifted out of the water for maintenance. [2]

Tidal stream turbines 1 a) generate power more reliably/tides

are more reliable than the wind; can generate more power from a smaller area [2]

b) accessibility – more difficult to maintain; more difficult to see when something has gone wrong; more difficult to build; harsher environment; ships can run into them. [2]

2 a) can generate electricity for a much higher proportion of the day; do not change the ecosystem around them. [2]

b) tidal barrages are easier to build and maintain, less harsh environment.

3 a) obstructions to water flow [1]

b) where the sea suddenly gets shallower. [1]

4 where there is a strong tidal stream that is easy to get to, little passing shipping [2]

5 It means that 1 kg of water will contain much more energy than 1 kg of air. [1]

6 Similarity: both make use of the tides Difference: barrage makes use of difference in tidal height, tidal stream turbine makes use of tidal stream. [2]

Extension worksheets U-values and buildings 1 a) to make homes more energy efficient

(or similar) [1]

b) It has made homes warmer and reduced heating bills. [2]

2 lower U-value because it is a poorer insulator and transmits more heat energy [2]

3 to keep heat out. [1]

4 a) by conduction. Particles at one side vibrate more and pass on energy when they collide with other particles. [2]

b) Heat is transferred to air particles by conduction when they collide with particles in the wall. Heat is transferred across the cavity by convection when a convection current is set up and particles move across the cavity. The particles then collide with the wall on the other side and heat energy is transferred by conduction through the other wall. [3]

c) It stops a convection current flowing. The insulator will also be a poor heat conductor. [2]

5 a) by radiation and conduction [2]

b) in the same way a cavity wall does – by reducing heat transfer by conduction [2]

c) It is much colder in winter in Sweden, so it is even more important to reduce heat losses. [1]

6 pupil’s own work but should include information on how new buildings should be carbon neutral [1] and an explanation of what this means [1] [2]

Coastal breezes 1 a) Land heats up quicker than the sea.

Warmer air rises, pulling in cooler air from over the sea. [2]

b) Direction of the wind will change – will bend more towards the south west. [2]

1 Answers


2 a) Land will cool down quicker than the sea. Warm air will rise over the sea, pulling in cooler air from the land. [2]

b) Wind direction will change more to the north west. [1]

3 Afternoon, because the wind direction will be south of west and so it will be able to sail a more direct path without needing to tack so much. [2]

4 a) Boat A will be able to sail a more direct course because the wind direction has changed more to the south west from the coastal breeze.. Boat B will have to tack to get there as the wind direction will not be changed by the influence of the coastal breeze. [4]

b) Boat A, because it will sail a more direct course. [1]

Documents

SECTION Energy transfers 1 - MR. HUSSAM PHYSICS 1.pdfEnergy transfers take place in many devices. You are going to investigate the energy transfers that take place in some everyday