5 the challenge in year 9wsassets.s3.amazonaws.com/ws/nso/pdf/edbc8d7ff... · 2011-06-06 ·...

The challenge in Year 9

Objectives

• To describe how conservation of energy can be used as an accounting systemduring energy transfers

• To provide one possible teaching strategy to develop pupils’ understanding ofconservation of energy

Resources

For tutor

Slides 5.0–5.3, 5.5, 5.6, 5.8–5.11, 5.15–5.23

Spare copies of the Framework for teaching science: Years 7, 8 and 9, or sparecopies of the yearly teaching objectives for energy (page 30)

Energy bricks

Flipchart and pens

For each participant

Handouts 5.4, 5.5, 5.7, 5.12–5.14, 5.21, 5.23 and 5.24

For pairs of participants

Handout 5.14 photocopied onto red card and cut up into individual tokens

Felt-tip pens

Scissors

For participants who have attended the Misconceptions in KeyStage 3 science CPD unit

A range of starters and plenaries illustrating energy transfer (optional)

Participants should bring:

Framework for teaching science: Years 7, 8 and 9

Session outline 1 hour

Progression into Year 9 Talk 5 minutesLooking at the yearly teaching objectives Whole groupfor Year 9

Ideas about energy Talk 10 minutesConsidering a scientist’s approach Whole group

123 | Strengthening teaching and learning of energy in Key Stage 3 science | Session 5| Notes for tutors

© Crown copyright 2003

5Session

Conservation of energy as a useful Demonstration, talk, 25 minutesaccounting system during energy task N, task Otransfers PairsUsing blocks or tokens with Sankey diagrams to show energy transfer, conservation and efficiency

Plenary Talk 20 minutesReflecting on the main points of the Whole groupsession and the unit

Progression into Year 9 5 minutes

Have slide 5.0 on display at the beginning of the session.

Show slide 5.1 and outline the objectives for the session.

Say that in this final session we will be looking at how the key scientific idea ofenergy develops in Year 9.

Show slide 5.2 about the Year 9 yearly teaching objectives for energy.



Session 5 Slide 5.0

The challenge in Year 9

Objectives for session 5 Slide 5.1



By the end of this session participants should:

• be able to show pupils how energy conservation can be used as an accountingsystem in science

• know how to use the conservation of energy to explain efficiency and dissipationof energy

• be able to use blocks or tokens with Sankey diagrams to illustrate conservation ofenergy

Slide 5.0

Slide 5.1

Slide 5.2

Ask participants to look at the Year 9 yearly teaching objectives and to identify theimportant areas of understanding that need to be developed in Year 9. Take somefeedback and then show slide 5.3.

Distribute handout 5.4 and talk participants through the important aspects ofteaching and learning about energy in Year 9.

Important aspects of teaching and learning energy in Year 9• In Year 9 the yearly teaching objectives for energy are broadly about applying

the idea of energy transfer to conservation of energy, efficiency and dissipation.

• Progression in the yearly teaching objectives is to:

– teach the idea of energy (mostly in Year 7);

– use the idea of energy (mostly in Year 8);

– apply the idea of energy (mostly in Year 9).

• Pupils find conservation of energy a challenging idea. Many state incorrectlythat some of the energy has disappeared at the end of an energy transferprocess; they do not see the need to ensure that all the available energy isaccounted for.

• Many pupils find support for this in everyday events. For example, they see thatmoving objects, such as cars, slow down and eventually stop and believe thisis because they have ‘run out of energy’. This incorrect explanation appearslogical to them.

• In this example there is no tangible evidence of energy having been transferredto anywhere else. By contrast, the fuel has been used up and needs to bereplaced, which unhelpfully reinforces misconceptions such as:

– fuel or food is energy, rather than an energy resource;

– energy is a type of stuff (although this possibly has a less negative impactthan the first misconception);

– energy is used up by processes and ‘runs out’.

• Pupils need to be convinced that looking for energy is worthwhile. One usefulapproach is to get them to account for energy transfers in everyday events. Forexample, identifying where energy is transferred when a formula one racing carslows down to go round a bend helps explain why the brake discs on the carglow red hot as it decelerates.

• It is useful to consider conservation of energy as an accounting system,because it helps move pupils away from energy as a causal agent. Energydoes not make things happen – it merely makes things possible.

• Using conservation of energy as an accounting system helps to reinforce acorrect understanding that energy:

– is not stuff or material;

– does not flow from one place to another, like a fluid.

It also helps to reinforce the idea of energy transfer, which means the sameenergy is located in different places.



Handout 5.4



Progression in Year 9 Slide 5.2

• Look at the yearly teaching objectives for energy in Year 9.

• What are the main teaching points in Year 9?

Progression in the yearly teaching objectives for energy Slide 5.3

Use the energy transfer model to explain phenomena in familiar and unfamiliar contexts

Heating Light Sound Respiration Ecology Rock Food and Chemical

cycle digestion reactions

Use a simple model of energy transfer

in situations including food chains and

webs and electric circuits

Explain the importance and uses

of stores of energy including food

and fuels

Apply energy conservation to explain

energy dissipation and energy

efficiency

Recognise the idea of energy

conservation as an accounting system

and how this can be applied to

energy transfers

Year 9

Year 8

Year 7

Slide 5.3

Handout 5.4

Ideas about energy 10 minutes

What do scientists think?

The material covered in this part of session 5 is the same as that outlined in theenergy section of the Misconceptions in science CPD unit. Some participants willhave attended that unit and so will have seen this material. Key Stage 3consultants and/or tutors will know, from Misconceptions in science attendanceregisters, who these participants are. You will need alternative activities for them.One approach is to ask these participants to evaluate a range of energy-relatedstarters and plenaries that you provide, or to generate some that they can use intheir own schools.

Show slide 5.5, which contains a statement from Richard Feynman about theabstract nature of energy.

The text is also reproduced on handout 5.5.

Allow participants time to read the slide or handout.

Say that:

• Richard Feynman (a Nobel laureate) was renowned for his ability tocommunicate scientific ideas.

• Energy is particularly difficult for pupils to understand because it is, as RichardFeynman said, ‘not a description of a mechanism, or anything concrete’.

• Feynman goes on to illustrate how a block model for energy transfer could beused to help understand the use of energy conservation as an accountingsystem.

Show slide 5.6 and ask participants to read the story on handout 5.7.



Energy – a most abstract idea Slide 5.5

‘There is a certain quantity, which we call energy, that does not change in themanifold changes which nature undergoes. That is a most abstract idea, because itis a mathematical principle; it says that there is a numerical quantity, which does notchange when something happens. It is not a description of a mechanism, oranything concrete; it is just a strange fact that we can calculate some number andwhen we finish watching nature go through her tricks and calculate that numberagain, it is the same.’

Richard Feynman

Slide 5.5

Slide 5.6

Handout 5.5

Handout 5.7 Richard Feynman’s model: Dennis the Menace Slide 5.6

Read handout 5.7.

Richard Feynman

Say that:

• Feynman’s idea of using blocks to represent little packets of energy and of theneed to look carefully to locate all the energy has been used by many teachersas a basis of an energy transfer teaching model. The blocks set a limit onwhat can be transferred.

• You saw in session 3 how transferring blocks can help pupils visualise energytransfers.

• Blocks or counters can also be used to introduce a quantitative aspect toenergy transfer.

Show slide 5.8 about energy transfer in an electric torch.

Dennis the Menace

Imagine Dennis who has blocks that are absolutely indestructible and cannot be divided into pieces. Each is the same as the other. Let us suppose he has 28.

His mother puts him with his 28 blocks into a room at the beginning of the day.

At the end of each day, being curious she counts them and discovers aphenomenal law. No matter what he does with the blocks, there are always 28 remaining.

This continues for some time until one day she only counts 27, but with a littlesearching she finds one under a rug. She realises she must be careful to lookeverywhere.

One day later she can only find 26. She looks everywhere in the room, but cannotfind them. Then she realises the window is open and the two blocks are foundoutside in the garden.

Another day, careful counts show there are 33 blocks. This causes considerabledismay until it is realised that Bruce came to visit bringing his blocks with him andleft a few.

She removes the five extra blocks and gives them back to Bruce and all returns tonormal.

We can think of energy like this except there are no blocks.

We can use this idea to track energy transfers during changes. We need to becareful to look everywhere to ensure that we can account for all the energy

(Adapted from Richard Feynman)



Handout 5.7



Energy transfers in an electric torch Slide 5.8

Slide 5.8

Say that:

• The numbers of blocks transferred to each place begin to suggest the relativeamounts of energy transferred by each process.

• For example, relatively little of the energy transferred from a conventionalfilament bulb (on the right-hand side of slide 5.8) is transferred by light(represented by one block) – most is transferred by heating (represented by four blocks).

• In contrast, almost all of the energy on the left-hand side of slide 5.8 istransferred from the cell to the bulb, when the electric current flows in the circuit(represented by five blocks). Relatively little is transferred from the cell to thesurroundings by heating (represented by one block). In fact, the amount ofenergy represented by one block is much too high here. Participants might liketo discuss how to show a smaller amount by considering fractions of a block orsmaller blocks.

• It is important to remember that the model needs to be ‘good enough’. It wouldbe possible to have 100 blocks and then to represent the energy transferredfrom the cell to the surroundings by heating more accurately using one block.However, using a large number of blocks would make it less obvious on slide5.8 that all the blocks have been accounted for.

Conservation of energy as a useful 25 minutes

accounting system during energy transfers

Many teachers introduce pupils to Sankey diagrams in Year 9. Sankey diagramsshould be seen as one way to demonstrate the energy transfer teaching model.

Show slide 5.9, which shows how a Sankey diagram can be used to illustrateenergy transfer in an electric torch.



A Sankey diagram showing energy transfers in an Slide 5.9electric torch

Cell Bulb Surroundings

Surroundings

Light

Heating

Heating

Electriccurrent

Slide 5.9

Demonstrate the animation of slide 5.9.

Say that:

• Blocks or tokens are used here to reinforce the idea of accounting for all theenergy – none of the blocks/tokens can be missed off the diagram.

• Pupils can construct their own Sankey diagrams using squared paper andtokens.

• This ‘hands on’ approach helps pupils visualise energy transfers. This is animportant step in their understanding of energy.

Show slide 5.10, which illustrates how pupils use tokens on Sankey diagrams.

Task N Helping pupils use the idea of energy 10 minutesconservation as an accounting system

Show slide 5.11, which gives instructions for task N.

Ask participants to work in pairs and to choose an energy story from handout 5.12. Make sure that each story has been chosen by at least one pair.Distribute squared paper (handout 5.13) and tokens and ask participants to usethese to represent their chosen story as a Sankey diagram.

Tell participants that handout 5.14 is supplied so that they can make tokens to usewith pupils back in school.



Using tokens with Sankey diagrams Slide 5.10

Task N Helping pupils use the idea of energy Slide 5.11conservation as an accounting system

• Choose one of the energy stories from handout 5.12.

• Use the squared paper (handout 5.13) and tokens supplied to make a Sankeydiagram representing the energy transfers in your chosen story.

Slide 5.10

Slide 5.11

Handout 5.12

Handout 5.13

Handout 5.14

Some participants may make their diagrams by sticking their tokens onto thesquared paper, as in the example on slide 5.10. Others may limit the number oftokens so that they have to move the tokens across the diagram and hence modelthe transfer process. Some participants may label the tokens with a value – say10 J.

As participants complete this task, circulate among them and prime an appropriatepair to demonstrate each of the aspects identified on slide 5.15 for task O.

Additional guidanceYou may need to model the process for participants if they are not familiar withSankey diagrams.

How useful are Sankey diagrams when used in this way?

Allow participants a few minutes to discuss the usefulness of using Sankeydiagrams with blocks or tokens when they teach about energy conservation. Haveslide 5.15 on display and use it to provide a context for discussion if necessary.

Task N Energy tokens



Handout 5.14

143

| Strengthening teaching and learning of energy in K

ey Stage 3 science |

Session 5

| N

otes for tutors©

Crow

n copyright 2003

Handout 5.13Task N Grid

Task N Energy stories

Choose one of the energy stories below.

Use the squared paper and tokens to draw a Sankey diagram to represent theenergy transfers in your chosen story.

1 A fire lighter stores 200 kJ of energy. When it burns, 190 kJ is transferred to thesurroundings by heating and 10 kJ by light.

2 Jayesh eats a chocolate bar at break time. The label says there is 1000 kJ ofenergy stored in the chocolate. As he runs around he transfers 600 kJ to thesurroundings by heating and 5 kJ by sound (that’s a lot of shouting!). Howmuch of the energy from the chocolate bar is left to be stored by Jayesh’s bodyat the end of break?

3 A ‘low-energy’ light bulb typically transfers about 80% of its energy to thesurroundings by light and the rest by heating.

4 Of every 1000 J of energy transferred to a hairdryer by the electric current, thehairdryer typically transfers about 800 J to the warm air by heating and movingit, about 190 J through the case to the person’s hands and about 10 J to thesurroundings by sound.

5 For every 50 J of energy transferred to the surroundings by sound, a portableCD player transfers another 300 J by heating.

6 The journey to the seaside uses 40 l of petrol. Janice has read that each litre ofpetrol stores 40 000 kJ of energy. She is curious to know where this energy hasbeen transferred to by the time the car stops. She wants to know how much ofthe energy is transferred to the moving car. Charlie says if all she wants to knowis where the energy is at the end, she doesn’t need to know anything about thecar at all!

7 Chris finds that a toy bow and arrow can store 20 J of energy when it is fullypulled back. When it is released, the bow transfers 10 J to the arrow, 6 J to thesurrounding air by heating, 3 J to the elastic of the bow itself by heating and1 J to the surroundings by sound.

8 A car engine is typically only 25% efficient. For every 100 J of energytransferred from the fuel, only 25 J ends up in the moving car. The rest istransferred to the surroundings by heating (70 J) and sound (5 J).



Handout 5.12



Slide 5.15

T

Task O Demonstrating the use of Sankey diagrams 15 minutes

Ask the pairs you primed during task N to demonstrate one of the following(selected from slide 5.15) using their Sankey diagrams:

• transfer of energy;

• conservation of energy;

• dissipation of energy;

• energy efficiency.

Take feedback on the strengths and limitations of using Sankey diagrams in thisway.

Additional guidance• Transfer of energy. Any of the energy stories except 3 and 6 should provide

an opportunity to demonstrate this. Pick a pair who have moved countersacross the diagram to show the transfer process, rather than a pair who stuckdifferent counters down at all stages of the transfer.

• Conservation of energy. Any of the stories should provide the opportunity toshow this.

• Dissipation of energy. Energy stories 4 and (possibly) 6 will provide anopportunity to exemplify dissipation. In story 4 the concentrated energytransferred to the hairdryer by the electric current is ‘spread out’ into severalsmaller, and therefore less useful, quantities in other places.

• Energy efficiency. This is the most challenging idea. Aim to prime one pair toprovide this feedback during the task. Ask them to show how the efficiency canbe calculated from their diagram. You may need to prompt them with theformula:

efficiency =useful energy transferredtotal energy transferred

Participants could do this using numbers of tokens or in joules if they haveassigned a value to each token. If appropriate, discuss why the answer will bethe same in a given story irrespective of whether participants use tokens orjoules.



The usefulness of Sankey diagrams Slide 5.15

How does using blocks or tokens with Sankey diagrams help pupils to understand:

• transfer of energy;

• conservation of energy;

• dissipation of energy (as energy is transferred it becomes more spread out and less useful);

• energy efficiency?

What are the limitations of using Sankey diagrams in this way?

T

If you have a small group, it may be necessary to model one or more of theaspects identified in task O yourself.

Points that may arise include:

• Moving the tokens across the diagram reinforces the idea of a transfer from oneplace to another.

• Having to account for all the tokens encourages pupils to look for where theenergy has gone and challenges the misconception that it simply disappears(you are not allowed to throw any tokens away).

• A lot of energy in one place at the start gradually gets broken down into smallerand smaller amounts with each successive transfer.

• Efficiency can be calculated by comparing the number of tokens (or the value ofthose tokens in joules) that end up in the desired location with the total numbertransferred.

• Dissipation can be introduced by looking at the smaller amounts of energylocated in a number of different places at the end of the transfer processcompared with the concentrated store of energy in one place at the start.

Limitations include:

• Sticking down tokens at each stage results in a proliferation of tokens, whichmay reinforce the misconception about creating and destroying energy.

• Energy is not a real thing like a token. The model may encourage pupils to thinkof energy as a substance. This is particularly problematic when dealing withheating.

• Energy does not come in finite packets. It may be quantised into packets insome circumstances, but there is no standard-sized energy packet.

• Energy is not red.

Plenary 20 minutes

Show slide 5.16, which gives the expected outcomes for the session.



Plenary for session 5 Slide 5.16

Objectives for session 5



By the end of this session participants should:

• be able to show pupils how energy conservation can be used as an accountingsystem in science

• know how to use the conservation of energy to explain efficiency and dissipationof energy

• be able to use blocks or tokens with Sankey diagrams to illustrate conservation ofenergy

Slide 5.16

Ask participants to review their progress against the outcomes during this sessionand to complete session 5 on their evaluation form.

Collect the evaluation forms.

An overview of the whole unit

Talk participants through the journey they have been on during the day using slides5.17–5.21. Show slide 5.17.

Say that:

• In session 1 we began by looking at what ideas pupils already have aboutenergy.

• Some of these ideas are drawn from everyday experiences and some from priorlearning.

Show slide 5.18.



How teaching at Key Stage 2 underpins the key idea of Slide 5.17energy at Key Stage 3

Year 7

6AInterdependenceand adaptation

6D Reversible and

irreversiblechanges

Use a simple model of energy transfer in situationsincluding food chains and webs and electric circuits

Explain the importance and uses of stores of energyincluding food and fuels

6G Changing circuits

6F How we see

things

6E Forces in action

5D Changing

state

5F Changingsounds

5A Keeping healthy

Slide 5.17

Slide 5.18

Say that:

• In session 2 we considered the possible places to start the explicit teachingabout energy in Year 7.

• Food as a store of energy was identified as one possible starting point.

Show slide 5.19.

Say that next, in session 3, we considered the two teaching models for energy andthe terminology associated with each.



The importance of context Slide 5.18

• Energy is a challenging abstract idea.

• Introducing energy through a familiar context will help pupils develop their ideasabout energy.

• Unfamiliar contexts are very challenging.

Energy Familiar contexts, such asliving things, torches, toyspowered by cells etc.

Unfamiliar contexts, such ashydroelectric dams, chemicalchange, respiration etc.

Alternative energy models for teaching energy at Slide 5.19Key Stage 3

Slide 5.19

Energy transformation Light

Heat

Chemical

Energy transfer

Heating

Light

Cell

Electrical

Electric current

Bulb

Surroundings

Show slide 5.20.

Say that:

• In session 4 we considered the way in which energy underpins many of thetopics taught in Year 8.

• The session highlighted that teachers have many opportunities to use the ideaof energy in familiar and unfamiliar contexts.

• We began a process of modifying learning objectives and activities, particularlyquestioning, to make the teaching of energy explicit.

Show slide 5.21. This slide is also provided as handout 5.21.





Slide 5.20

Slide 5.21

Handout 5.21









and fuels

Year 8

Year 7









and fuels

Apply energy conservation to explain

energy dissipation and energy

efficiency

Recognise the idea of energy

conservation as an accounting system

and how this can be applied to

energy transfers

Year 9

Year 8

Year 7

Say that:

• Finally, in session 5, we considered the challenge in Year 9.

• Pupils need to be taught about energy conservation and how to use energyconservation as an accounting system.

• We looked at one way the token or block model could be adapted to supportpupils in this difficult area.

• We discussed the usefulness of this approach in tackling energy efficiency anddissipation.

• We also considered the limitations of the energy transfer model.

Ask participants to find their true or false activity from the start of the day (task A insession 1).

Show slide 5.22.

Allow participants to spend 5 minutes reflecting on their answers and takefeedback on any areas in which they have changed their views.

Where next?

Show slide 5.23, which has some ideas for follow-up actions in schools.



Energy: true or false? Slide 5.22

• Have you changed any of your views about energy during the day?

• Think of one thing you will do differently the next time you teach pupils aboutenergy.

Where next? Slide 5.23a

Individually

• Be explicit with pupils about when the idea of energy is being introduced, perhapsby using the energy stored in food as a starting point.

• Allow time to explain to pupils that there are two teaching models to explain theidea of energy. These are transformation of energy and energy transfer.

• Be precise about the terminology that is used for the transformation and transferteaching models. Mixing the two into a hybrid language will probably confusepupils.

Where next? Slide 5.23b

Individually

• Recognise that pupils will meet both teaching models in textbooks and end of KeyStage 3 tests.

• Be more selective when using activities and examples taken from textbooks.

• Provide opportunities for pupils to develop their understanding of the idea ofenergy by practising using energy terminology to explain a range of changes,events and phenomena.

• Identify lessons in which pupils can use the energy transfer teaching model in Year 8.

Slide 5.22

Slide 5.23

Ask participants to look at handout 5.23, which is a copy of the slides.



Where next? Slide 5.23c

Individually

• Use ideas of energy transfer when teaching light.

• Generate some questions to use in existing lessons that challenge and extendpupils’ thinking about energy.

• Modify some existing departmental resources to ensure consistency in the use ofappropriate terminology.

• Discuss with more able pupils the role played by models in science.

• Use tokens with Sankey diagrams to develop the idea of energy conservation.

Where next? Slide 5.23d

As a department

• Work with the Key Stage 3 science coordinator to plan for an explicit introductionof the idea of energy to pupils in Year 7.

• Work with the Key Stage 3 science coordinator to check the progression ofenergy ideas and the use of models in your scheme of work.

• Analyse pupils’ responses to internal tests and end of Year 9 tests, and use theKey Stage 3 standards reports for science to pinpoint pupils’ difficulties with theidea of energy and its associated language.

Where next? Slide 5.23e

As a department

• Develop a progressive teaching programme based on the yearly teachingobjectives for energy.

• Encourage greater consistency in the use of the energy transfer teaching modelterminology to promote better understanding of the ideas of energy conservation,dissipation and efficiency.

• Use the true or false activity and the energy cards in a department meeting topromote discussion of energy ideas and terminology.

• Help initiate department INSET based on today’s course, perhaps with supportfrom the LEA consultant.

Handout 5.23

Handout 5.24 is a grid that participants can use to fill in their plans for follow-upactions in school. They may choose actions from handout 5.23 or they may haveideas of their own. You may like to photocopy the completed copies of handout5.24 as your own record of areas to follow up on your next school visit.

Follow-up work at school



Handout 5.24

Name: School:

Actions Year Notes

7 8 9

Give feedback about the courseto my head of department and/or Key Stage 3 science coordinator

Report back the ideas from this course to a department meeting

Help identify other staff who would benefit from attending this training

Wit

hin

the

dep

artm

ent

In m

y o

wn

teac

hing



Handout 5.24

Important aspects of teaching and learning energy in Year 9• In Year 9 the yearly teaching objectives for energy are broadly about applying

the idea of energy transfer to conservation of energy, efficiency and dissipation.

• Progression in the yearly teaching objectives is to:

– teach the idea of energy (mostly in Year 7);

– use the idea of energy (mostly in Year 8);

– apply the idea of energy (mostly in Year 9).

• Pupils find conservation of energy a challenging idea. Many state incorrectlythat some of the energy has disappeared at the end of an energy transferprocess; they do not see the need to ensure that all the available energy isaccounted for.

• Many pupils find support for this in everyday events. For example, they see thatmoving objects, such as cars, slow down and eventually stop and believe thisis because they have ‘run out of energy’. This incorrect explanation appearslogical to them.

• In this example there is no tangible evidence of energy having been transferredto anywhere else. By contrast, the fuel has been used up and needs to bereplaced, which unhelpfully reinforces misconceptions such as:

– fuel or food is energy, rather than an energy resource;

– energy is a type of stuff (although this possibly has a less negative impactthan the first misconception);

– energy is used up by processes and ‘runs out’.

• Pupils need to be convinced that looking for energy is worthwhile. One usefulapproach is to get them to account for energy transfers in everyday events. Forexample, identifying where energy is transferred when a formula one racing carslows down to go round a bend helps explain why the brake discs on the carglow red hot as it decelerates.

• It is useful to consider conservation of energy as an accounting system,because it helps move pupils away from energy as a causal agent. Energydoes not make things happen – it merely makes things possible.

• Using conservation of energy as an accounting system helps to reinforce acorrect understanding that energy:

– is not stuff or material;

– does not flow from one place to another, like a fluid.

It also helps to reinforce the idea of energy transfer, which means the sameenergy is located in different places.



Handout 5.4

Energy – a most abstract idea

‘There is a certain quantity, which we call energy, that does

not change in the manifold changes which nature undergoes.

That is a most abstract idea, because it is a mathematical

principle; it says that there is a numerical quantity, which does

not change when something happens. It is not a description of

a mechanism, or anything concrete; it is just a strange fact

that we can calculate some number and when we finish

watching nature go through her tricks and calculate that

number again, it is the same.’

Richard Feynman



Handout 5.5

Dennis the Menace

Imagine Dennis who has blocks that are absolutely indestructible and cannot be divided into pieces. Each is the same as the other. Let us suppose he has 28.

His mother puts him with his 28 blocks into a room at the beginning of the day.

At the end of each day, being curious she counts them and discovers aphenomenal law. No matter what he does with the blocks, there are always 28 remaining.

This continues for some time until one day she only counts 27, but with a littlesearching she finds one under a rug. She realises she must be careful to lookeverywhere.

One day later she can only find 26. She looks everywhere in the room, but cannotfind them. Then she realises the window is open and the two blocks are foundoutside in the garden.

Another day, careful counts show there are 33 blocks. This causes considerabledismay until it is realised that Bruce came to visit bringing his blocks with him andleft a few.

She removes the five extra blocks and gives them back to Bruce and all returns tonormal.

We can think of energy like this except there are no blocks.

We can use this idea to track energy transfers during changes. We need to becareful to look everywhere to ensure that we can account for all the energy.

Adapted from Richard Feynman



Handout 5.7

Task N Energy stories

Choose one of the energy stories below.

Use the squared paper and tokens to draw a Sankey diagram to represent theenergy transfers in your chosen story.

1 A fire lighter stores 200 kJ of energy. When it burns, 190 kJ is transferred to thesurroundings by heating and 10 kJ by light.

2 Jayesh eats a chocolate bar at break time. The label says there is 1000 kJ ofenergy stored in the chocolate. As he runs around he transfers 600 kJ to thesurroundings by heating and 5 kJ by sound (that’s a lot of shouting!). Howmuch of the energy from the chocolate bar is left to be stored by Jayesh’s bodyat the end of break?

3 A ‘low-energy’ light bulb typically transfers about 80% of its energy to thesurroundings by light and the rest by heating.

4 Of every 1000 J of energy transferred to a hairdryer by the electric current, thehairdryer typically transfers about 800 J to the warm air by heating and movingit, about 190 J through the case to the person’s hands and about 10 J to thesurroundings by sound.

5 For every 50 J of energy transferred to the surroundings by sound, a portableCD player transfers another 300 J by heating.

6 The journey to the seaside uses 40 l of petrol. Janice has read that each litre ofpetrol stores 40 000 kJ of energy. She is curious to know where this energy hasbeen transferred to by the time the car stops. She wants to know how much ofthe energy is transferred to the moving car. Charlie says if all she wants to knowis where the energy is at the end, she doesn’t need to know anything about thecar at all!

7 Chris finds that a toy bow and arrow can store 20 J of energy when it is fullypulled back. When it is released, the bow transfers 10 J to the arrow, 6 J to thesurrounding air by heating, 3 J to the elastic of the bow itself by heating and1 J to the surroundings by sound.

8 A car engine is typically only 25% efficient. For every 100 J of energytransferred from the fuel, only 25 J ends up in the moving car. The rest istransferred to the surroundings by heating (70 J) and sound (5 J).



Handout 5.12



Han

do

ut 5

.13

Task

N

Gri

d

Task N Energy tokens



Handout 5.14

Pro

gre

ssio

n i

n t

he y

earl

y te

achin

g o

bje

cti

ves

for

energ

y



Han

do

ut 5

.21

Use

the

ene

rgy

tran

sfer

mod

el t

o ex

plai

n ph

enom

ena

in fa

milia

r an

d un

fam

iliar

cont

exts

Hea

ting

Ligh

tS

ound

Res

pira

tion

Eco

logy

Roc

k Fo

od a

nd

Che

mic

al

cycl

edi

gest

ion

reac

tions

Use

a s

impl

e m

odel

of e

nerg

y tr

ansf

er

in s

ituat

ions

incl

udin

g fo

od c

hain

s an

d

web

s an

d el

ectr

ic c

ircui

ts

Exp

lain

the

impo

rtan

ce a

nd u

ses

of s

tore

s of

ene

rgy

incl

udin

g fo

od

and

fuel

s

App

ly e

nerg

y co

nser

vatio

n to

exp

lain

ener

gy d

issi

patio

n an

d en

ergy

effic

ienc

y

Rec

ogni

se t

he id

ea o

f ene

rgy

cons

erva

tion

as a

n ac

coun

ting

syst

em

and

how

thi

s ca

n be

app

lied

to

ener

gy t

rans

fers

Year

9

Year

8

Year

7

Teaching pupils about energy –possible points for action

Individually• Be explicit with pupils about when the idea of energy is being introduced,

perhaps by using the energy stored in food as a starting point.

• Allow time to explain to pupils that there are two teaching models to explain theidea of energy. These are transformation of energy and energy transfer.

• Be precise about the terminology that is used for the transformation andtransfer teaching models. Mixing the two into a hybrid language will probablyconfuse pupils.

• Recognise that pupils will meet both teaching models in textbooks and end ofKey Stage 3 tests.

• Be more selective when using activities and examples taken from textbooks.

• Provide opportunities for pupils to develop their understanding of the idea ofenergy by practising using energy terminology to explain a range of changes,events and phenomena.

• Identify lessons in which pupils can use the energy transfer teaching model inYear 8.

• Use ideas of energy transfer when teaching light.

• Generate some questions to use in existing lessons that challenge and extendpupils’ thinking about energy.

• Modify some existing departmental resources to ensure consistency in the useof appropriate terminology.

• Discuss with more able pupils the role played by models in science.

• Use tokens with Sankey diagrams to develop the idea of energy conservation.

As a department• Work with the Key Stage 3 science coordinator to plan for an explicit

introduction of the idea of energy to pupils in Year 7.

• Work with the Key Stage 3 science coordinator to check the progression ofenergy ideas and the use of models in your scheme of work.

• Analyse pupils’ responses to internal tests and end of Year 9 tests, and use theKey Stage 3 standards reports for science to pinpoint pupils’ difficulties with theidea of energy and its associated language.

• Develop a progressive teaching programme based on the yearly teachingobjectives for energy.

• Encourage greater consistency in the use of the energy transfer teaching modelterminology to promote better understanding of the ideas of energyconservation, dissipation and efficiency.

• Use the true or false activity and the energy cards in a department meeting topromote discussion of energy ideas and terminology.

• Help initiate department INSET based on today’s course, perhaps with supportfrom the LEA consultant.



Handout 5.23

Follow-up work at school



Handout 5.24

Name: School:

Actions Year Notes

7 8 9

Give feedback about the courseto my head of department and/or Key Stage 3 science coordinator

Report back the ideas from this course to a department meeting

Help identify other staff who would benefit from attending this training

Wit

hin

the

dep

artm

ent

In m

y o

wn

teac

hing

Strengthening teaching and learning of energy in Key Stage 3 science• Energy is a key scientific idea which is first taught explicitly at Key Stage 3; it

permeates science at this age range and thereafter.

• There are a number of common misconceptions that pupils can hold aboutenergy – for example, that energy is ‘stuff’, or that it is ‘used up’, or that it‘makes things happen’. An awareness of pupils’ misunderstandings andmisconceptions and the appropriate use of teaching models can helpovercome these.

• It is important that teaching about energy as a key scientific idea is started earlyin Year 7 in a way that is made explicit to pupils.

• The yearly teaching objectives set out a progression in the key idea of energythat moves from teaching pupils about energy in Year 7, to using ideas aboutenergy in Year 8, to applying energy ideas in Year 9 (see handout 5.21).

• Transformation of energy and energy transfer are two ways of teaching(teaching models) about the key scientific idea of energy; they do not describetwo different scientific ideas. For example, handout 3.8 outlines how the energystory of a torch can be described in two ways.

• The two ways of teaching (teaching models) about energy are characterised byassociated terminology; it is important to use terminology consistently so thatpupils do not become confused.

• It may be acceptable to use two ways of teaching (teaching models) aboutenergy in Year 7, to enable pupils to move from concrete understanding aboutenergy to a more abstract understanding; in addition, textbooks andexamination questions use the terminology interchangeably.

• The energy transfer teaching model offers advantages over the transformationof energy teaching model in the development of pupils’ understanding ofconservation of energy as a useful scientific accounting system. The Key Stage3 science advice is that energy transfer should be the teaching modelconsistently used during Year 8 and Year 9.

• Pupils need opportunities to develop their understanding of energy in a range oftopics, such as ecology, heating and cooling, light, sound, chemical reactionsand electricity.

• During topics that use or apply the idea of energy, specific energy-relatedquestions can be asked and/or lesson objectives modified so that pupils haveas many opportunities as possible to reinforce their understanding of energy.

• Focused and explicit questioning about energy in a range of different contextsor topics, such as heating, light and sound, is a good way to challenge pupils’understanding of energy.



Main messages



• Blocks or tokens can be used to enhance the effectiveness of Sankey diagramsin the teaching of conservation of energy as an accounting system.

• Pupils’ understanding of efficiency and dissipation of energy can be developedby the effective use of Sankey diagrams.

Implications for the science department

Many of the messages from this unit are for individual teachers to implement intheir own teaching of energy. The work of individual teachers could be enhancedthrough a departmental discussion of some wider issues, such as planning forprogression in the teaching of energy and the use of consistent terminology acrossthe department. In particular, participants may find it helpful to discuss some of thecourse materials with a physics or physical sciences teacher. A summary of somepossible points for action is included below. A more detailed menu of activities canbe found on handout 5.23.

• Review the department scheme of work by:

– identifying an explicit introduction of energy as a key scientific idea to pupilsearly in Year 7;

– checking the progression of energy as a key scientific idea from Year 7,through Year 8 and into Year 9.

• Analyse pupils’ responses to internal tests and Year 9 national tests, and usethe QCA Standards at Key Stage 3: science report to pinpoint pupils’ difficultieswith the idea of energy and its associated terminology.

• Encourage greater consistency across the department in the use of terminologywhen teaching about energy.

Implications for individual teachers

• Give feedback about the CPD unit to the head of department and/or Key Stage3 science coordinator.

• Allow time to explain to pupils that, in science, models and analogies need tobe refined and/or replaced. Transformation of energy and energy transferteaching models provide a good example of when one model replaces anotherto help pupils develop a deeper understanding about energy, particularly theconservation of energy.

• Be precise about the terminology that is used for transformation of energy andenergy transfer teaching models. Mixing the two using hybrid terminology islikely to confuse pupils.

• Modify existing departmental resources to ensure consistency in the use ofenergy terminology, recognising that pupils will meet both teaching models intextbooks and examination questions.

Alt

ern

ati

ve m

odels

for

teachin

g e

nerg

y at

Key

Sta

ge 3



Han

do

ut 3

.8

Ene

rgy

tran

sfo

rmat

ion

Ligh

t

Hea

t

Che

mic

al

Ene

rgy

tran

sfer

Hea

ting

Ligh

t

Cel

l

Ele

ctric

al

Ele

ctric

cur

rent

Bul

b

Sur

roun

ding

s

Pro

gre

ssio

n i

n t

he y

earl

y te

achin

g o

bje

cti

ves

for

energ

y



Han

do

ut 5

.21

Use

the

ene

rgy

tran

sfer

mod

el t

o ex

plai

n ph

enom

ena

in fa

milia

r an

d un

fam

iliar

cont

exts

Hea

ting

Ligh

tS

ound

Res

pira

tion

Eco

logy

Roc

k Fo

od a

nd

Che

mic

al

cycl

edi

gest

ion

reac

tions

Use

a s

impl

e m

odel

of e

nerg

y tr

ansf

er

in s

ituat

ions

incl

udin

g fo

od c

hain

s an

d

web

s an

d el

ectr

ic c

ircui

ts

Exp

lain

the

impo

rtan

ce a

nd u

ses

of s

tore

s of

ene

rgy

incl

udin

g fo

od

and

fuel

s

App

ly e

nerg

y co

nser

vatio

n to

exp

lain

ener

gy d

issi

patio

n an

d en

ergy

effic

ienc

y

Rec

ogni

se t

he id

ea o

f ene

rgy

cons

erva

tion

as a

n ac

coun

ting

syst

em

and

how

thi

s ca

n be

app

lied

to

ener

gy t

rans

fers

Year

9

Year

8

Year

7

5 the challenge in year 9wsassets.s3.amazonaws.com/ws/nso/pdf/edbc8d7ff... · 2011-06-06 ·...

Documents