Meldrum Academy
Science Faculty
S1 - Energy and Heat
Name ……………………………………………………………
Class …………………………………
Energy Learning Outcomes / / /· State that energy can be changed from one form to another (Level C)
· Give examples of energy being changed (or converted ) from one form to another(Level C)· State the energy change in a bell, lamp and buzzer. (Level C)
· State that the kinetic energy is the energy a body has as a result of its movement. (Level E)
· State that gravitational potential energy is a type of energy a body has due to its position above the Earth’s surface. (Level E)
· State that gravitational potential energy can be changed to kinetic energy and vice versa (Level E)
· Give examples of the conversion of gravitational potential energy to kinetic energy and kinetic energy to gravitational potential energy (Level E)
· State that chemical energy is a type of stored energy. (Level E)
· State that chemical energy is stored in batteries, food and fuels (Level E)
· Give examples of chemical changes. (Level E)
· State that gravitational potential energy of an object is related to the height of the object (Level F)
· State that the chemical energy of an object is due to its chemical composition. (Level F)
Heat Learning Outcomes / / /
· Heat is a form of energy and is measured in joules (level D)
· Temperature is a measure of the hotness of an object and is measured in degrees Celsius (level D)
· Adding heat to an object increases its temperature and losing heat leads to a drop in temperature (level D)
· Metals are good conductors of heat (level C)
· Heat flows from hot objects to cold objects (level E)
· Heat travels by conduction when the particles vibrate more and pass the energy from particle to particle (level E)
· Convection can happen in liquids or gases (fluids)
In convection some particles rise transferring heat energy (level E)
· Good conductors allow heat to flow through them easily (level E)
· Poor conductors are called insulators (level E)
· Be able to give examples of good and poor conductors of heat (level E)
· Trapped air is a good insulator (level E)
· Heat energy can be transferred as radiation (level F)
· Heat is also called infrared radiation (level F)
· Dull black surfaces lose heat by radiation much faster than shiny, polished surfaces (level F)
On Earth we get all of our energy from the SUN.
What is energy??
We need energy for everything we do. Name 3 things that we do that need energy.
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When energy gets changed or transferred from one form to another it is called an energy transfer. We show these energy transfers by using arrows in an energy transfer diagram.
Example 1 - A bonfire changes energy which has been stored in the wood into heat and light and even some sound.
Energy transfer diagram for the bonfire
Chemical energy à heat energy + light energy + sound energy
Example 2 - A wind-up radio
k…………..…………….. energy à s………..………… energy
Example 3 - An electric kettle
E………………………….. energy à ……….……….. and ………..………. energy
Energy Transfer Experiments
Practical 1 - Energy Transfer Experiments
§ Carefully read and follow the instruction cards at the stations.
§ Your teacher will tell you which station to start at.
This is an example of the standard of write-up expected.
1. Battery, switch and bell circuit
c…………..…………. e………………. è e…………………….. e………………è s……………….. e……………
2. Battery, switch and bulb circuit.
c…………..… e………………. è e……………….. e………………è h……………….. e………………….. +
l………………….. e……………….
The unit of energy is called the JOULE. This is called after a famous Scottish scientist James Joule who did many experiments in energy and heat. It is usually shortened to the symbol ”J”.
One joule is a small amount of energy and we usually need to talk about kilojoules.
1 kilojoule = 1000 Joules
In symbols this is written 1 kJ = 1000J
Stored or potential energy
Energy can be stored in three ways:-
§ as chemical energy,
§ by lifting objects up ( gravitational potential energy)
§ by changing an objects shape (strain energy or elastic potential energy)
We can release and use this stored energy.
1) Chemical energy – fuels and food store chemical energy.
A fuel is burned to release its stored energy, eg oil and gas in Boddam Power station.
Food is eaten and then the energy is released into the cells of the body by respiration. More on this in your Biology units.
2) By lifting objects up
Stored energy is called p………..…………………. energy. If we lift an object upwards we have to do work against the force of gravity. This is stored in the object as g……………………………. p…………….…………… e……………….……. until it is released and allowed to fall back down. Water trapped behind a dam can be released to generate e………………..…………. energy
3) By changing shape – teacher Demonstration
We can store energy by changing the shape of an object. We can do this by stretching them, twisting them, bending them, squeezing them. We put the material under strain so this type of stored energy is called strain energy.
Write down two examples of strain energy as shown by your teacher.
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Examples of potential energy are shown in the box below.
Complete the table below by arranging all of the potential energies shown in the box into either: chemical energy, gravitational energy or strain energy
Potential EnergyChemical Energy / Gravitational potential energy / Strain
4) Circle the object with the most potential energy from the pairs below.
§ A small apple on a branch of a tree 3m above the ground
§ A small apple on a branch 5 m above the ground
§ A granite stone on top of an 8m building
§ A pebble on top of an 8m building
§ A pencil on a desk
§ A jet cruising at 1000m altitude.
5) Write out energy transfers for these situations:-
A) A girl swinging on a swing
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B) A lump of wood burning on a fire
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C) A firework rocket exploding in the sky
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D) A boy playing hockey
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6 Energy changes involved in a ski jump .
a) Name the two types of energy shown in the diagram
KE …………………………………………………. PE ……………………………..…………………………….
b) What type of energy does the skier have at the start (top of the hill)?
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c) How many joules of energy does the skier have at the start?
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d) Describe the energy change as he skis down the hill ( From100m height to 30m height)
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e) What do you observe about the TOTAL amount of energy at any point?
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f) Describe his energy at the end of the run?
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7) A diver jumps off a diving board, which is 2m above a swimming pool, She has 1000 Joules of Potential Energy at the start.
a) Produce one sketch, showing the diver at three different positions during her dive :- before leaving the board, half-way down and just before entering the water.
b) How much Kinetic energy does the diver have just before she dives off the board? ………………………………………………………………
c) How much Potential energy does the diver have when she is 1m above the water? …………………………………………………………………………
d) How much Kinetic energy does the diver have when she is 1m above the water? …………………………………………………………………………………
e) How much Kinetic energy does the diver have just before she hits the water? ………………………………………………………………………………………
f) How much Potential energy does the diver have just before she hits the water? ………………………………………………………………………………………
g) Label your sketch with the energy values. Use your answers from above.
h) In reality the answer to question d is 950 Joules. What has happened to the rest of the energy? ……………………………………………………………………………………
Energy Arrows
Read page 29 of Starting Science Book 1. Go and investigate the electric circuit Practical 3 on the side bench.
Copy and label the circuit diagram
1) Name the components in the circuit
A………………………… B ………………….……… C …………………………
D ……………………… E …………………….
2) For each component, what are the energy changes shown in the Sankey diagram G, H and I? Use the colour of the arrows to help you.
F Chemical energy è electricity + heat
G ……………………………………………………………………………………………………………………………..
H ……………………………………………………………………………………………………………………………
I …………………………………………………………………………………………………………………………….
3) Draw a Sankey Diagram for component E.
More Sankey diagrams
Here is a Sankey diagram for a car. Notice most of the energy from the petrol is not transferred to kinetic energy at all. It heats up the surroundings (the engine block, the oil, the cooling water, the tyres, the car body, the air around the car).
What is another term for heat energy? …………………………………
Complete the table. Use the Sankey diagram above to help you.
Where energy from burning petrol is transferred / Percentage %to the surroundings as heat energy
to the surroundings as sound
to the car as kinetic energy
TOTAL =
Name 5 appliances found at home that are designed to change electrical energy onto heat.
1…………………………………………………………………………………………………………………………………………………………
2……………………………………………………………………………………………………………………………………………………….
3……………………………………………………………………………………………………………………………………………………….
4…………………………………………………………………………………………………………………………………………………………
5……………………………………………………………………………………………………………………………………………………….
More than one energy change
Copy and complete this table.
Electrical appliance / Useful energy(s) (energy we do want) / Wasted energy(Energy we do not want)
Kettle
Food mixer
Light bulb
Television
1. What are the most common forms of “wasted energy” ?
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2. Write out the energy changes involved in a plane at take off.
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3. Describe the forms of energy which are” wasted” in a plane taking off.
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4. Think of ways of reducing this “wasted energy” in a plane.
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Possible Revision Work
Create a “spider diagram” summary sheet.
OR do the revision quiz below.
Revision Quiz
1) Name 7 types of energy
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2) Name 3 types of stored energy
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3) Energy is measured in units called …………………………..
4) Draw an energy transfer diagram for a battery powered torch.
5) What type of energy is stored in petrol? …………………………………………………………………………
6) What is the main type of energy produced by a car?
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7) What is the Law of Conservation of energy?
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8) Complete the Sankey Diagram below.
We are now going to look at heat energy in more detail.
Heat or temperature
Everything is made of particles – atoms and molecules. If we supply heat to a material the particles gain energy and the particles will move faster and vibrate more. If the material loses energy the, size of vibrations get smaller. The temperature at which the particles stop vibrating is called absolute zero. This temperature is - 273 oC.
Heat is not the same as temperature.
Temperature is a measure of hotness or coldness and is measured in d……………………………. C………………………….. (oC).
Heat is a measure of the total energy in the material. It is measured in J………………… (J). The amount of heat energy depends on the mass , the type of material and the temperature.
· compare the bath of warm water to the kettle of boiling water.
· Explain why the bath has more total energy than the kettle.
……………………………………………………………………………………………………………………………………………………………………………………………………………………………...………………………………………………………..
Heat always flows from HOT to COLD
Change of State
There are three methods of heat transfer through different materials.
They are called CONDUCTION, CONVECTION AND RADIATION.
CONDUCTION
Practical 6 - Collect the conduction equipment, a stopwatch and a kettle
a) Draw and label this piece of apparatus into your jotter.
b) What do all the rods have in common?
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c) Complete the results table.
Rod material
/ Time for drawing pin to drop off (seconds)Answer these questions in sentences.
1. Why did the drawing pins fall off?
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2. Which method of heat transfer allows heat to travel through metals?
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3. Which material was the best conductor in the above experiment?
Explain your answer. …………………………………………………………………………….……..
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4.What would happen is you used a wooden rod in this activity?
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5.Which would you use to stir boiling soup in a pan, a wooden spoon or a metal spoon? Explain you answer. …………………………………………………………………….
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· Complete this note on CONDUCTION of heat.
Practical 7 – CONVECTION
Part A Potassium Permanganate Dye in water
Diagram
1) What can you say about the movement of warm liquids?
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2) The path taken by the purple dye is called a
C…………………………………………………. C…………………………..
3) Explain why cakes cook quickest on the top shelf of an oven.
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PartB Green ice cube in warm water
Diagram
What can you say about the movement of cold liquids?
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Part C
· Show what happens when the warm and cold water mixes.
· Colour the warm water red.
Before the lid is removed After the lid is removed
Why does the warm liquid rise?
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Explain why a refrigerator is colder at the bottom than at the top.
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Part D
Watch the “Smoke – box” demonstration.
Why does the smoke move in this way?
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· Complete the note on convection.
RADIATION OF HEAT
Practical 8 - An Investigation to find out if shiny flasks or flack flasks are best at radiating heat.