Notes for Teachers:
Heat on the Move.
There are 5 aspects to this package.
A simulation of an investigation into the 3 main mechanisms of heat transfer.
An animation to show how particles are involved in the transfer of heat energy.
A simulation investigating the emitted radiation from different surfaces.
An interactive visual where heat loss from a house can be demonstrated by
shading with thermal imaging colours.
Revision questions to test pupils’ knowledge, included within this PDF document.
Part one:
The simulation is based on a beaker that can be filled with hot water. Temperature probes can be placed
at certain points around the beaker in order to monitor the heat loss through conduction, convection and
radiation.
The positions of the 4 temperature probes are shown below:Position A: the probe is placed in the hot water.
Position B: the probe is placed on the outside of the beaker but touching the glass. This is designed to
monitor the conduction of heat through the glass.
Position C: the probe is placed on the outside of the beaker just above the top. This is designed to
monitor the convection of heat from the outer surface of the beaker.
Position D: the probe is placed on the outside of the beaker but away from the glass wall. This is
designed to monitor the radiation of heat by the hot outer wall.
The user can experiment by using no insulation, side insulation, top insulation or complete insulation. By
positioning the suitable probes, and choosing the appropriate insulation, it is possible to investigate how
effective the insulation is in controlling conduction, convection or radiation.
Suggestions of usage:
The teacher can display the simulation in real-time and watch the data as it is collected, however this will
be quite time-consuming and therefore we can accelerate time using the x10 option.
An alternative would be to run the experiment with no insulation and then ask how the graph would be
different when the beaker is insulated in different ways.
It could also be useful to get the students to explain how the probes indicate whether heat is being
transferred by conduction, convection or radiation.
Part two:
Using the animation.
The purpose of the animation is to show how particles exchange energy causing a transfer of heat
energy. The animation shows a hot water tank. With no insulation heat energy is transferred from the
liquid through the metal tank to the outside (by conduction) and then to the air (showing expansion,
density reduction and hence convection). By adding side insulation we can show how the barrier
between the tank outside and the air prevents heat loss by convection.
The purpose of the animation is to attempt to illustrate the way particle movement can explain the
transfer of energy.
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Notes for Teachers: Continued
Part three:
Using a simulation of the Leslie’s cube experiment.
A metal box is filled with hot water. Each of the four sides has a different surface colour. The
temperature of the side is taken using an infrared thermometer.
By rotating the box we can take the temperature of each side in turn to investigate the amount of emitted
radiation. The simulation clearly shows that dull black surfaces are better emitters of the radiation than
shiny or white surfaces.
The infrared thermometer indicates a temperature according to the intensity and wavelength of emitted
radiation. As hot black surfaces emit more radiation the thermometer registers this has a higher
temperature.
Part four:
Using thermal images.
Having made the link between temperature and the amount of heat radiation using the Leslie’s cube
demonstration we can now look at thermal imaging as a way of investigating the effectiveness of
different types of insulation.
The screen presents two outlines of a house. The idea is to “colour in” various parts of the house
according to what temperature the surfaces may be at. For example you may wish to set up a scenario
where one house has loft insulation whilst the other does not. Pupils can then suggest whether the roof
space will be warm or not and therefore attribute a colour to indicate the value of the roof temperature.
The purpose here is to get pupils to think about how insulating different parts of the houses would affect
the energy loss from the house. Clearly any scenario depends on the internal and external temperatures
and these form part of the teachers initial discussions with the class.
It is possible to find thermal images of a host of different situations on the internet and this can widen up
a discussion to include uses of thermal imaging from energy efficiency to searching for earthquake
victims.
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Revision Questions
1. Conduction of heat occurs best in ______________ .
2. Hot black surfaces are better ____________ of infra-red than hot shiny surfaces.
3. Convection takes place in _________ and gases because the particles can move.
4. Infra red is the name we give to ________________ .
5. Metals conduct heat better than plastics because their ________________ are closer together.
6. When air gets hot it ________________ and rises.
7. The diagram opposite shows two hot
water tanks, one of which is insulated with
plastic foam.
metal
tank
hot water
foam
jacket
electrical
heater
hot water
Explain, in terms of particles, how the heat energy is lost from the un-insulated tank.
How does the plastic foam reduce heat loss?
Why is the electrical heater put at the bottom of the tank?
Can you think of a disadvantage of putting the heater at the bottom as opposed to halfway up?
8. A beaker of hot water has 4 temperature
probes in or around it. The temperature
probes record the temperature as the
beaker cools down. The diagram shows
the places where the probes have been
placed.
On the graph sketch how the temperatures
of each probe will change over 10 mins
from the time boiling water is poured in.
temperature
A
D
C
The beaker is now insulated around the sides.
Sketch on the graph opposite how the temperature
of each probe will change if the experiment is
repeated.
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B
time
temperature
time
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