Lesson Plan

Teaching Sequence

Work through this resource material in the following sequence:

10 minutes

Tune In: What is thermal energy, and how is it transferred?

20 minutes

Find Out: What are the different methods of thermal energy transfer?

25 minutes

Take Action: Applications of thermal energy transfer

5 minutes

Reflection

Tune In: What is thermal energy, and how is it transferred?

Step 1

Use the following demonstration to introduce your students to the concept of thermal energy. You could run this as a group experiment or as a demonstration to save time and resources.

Materials required:

3 x soft drink cans	3 x thermometers
3 x plastic tubs	Hot water
Ice

Place each can of soft drink (opened) into the three tubs and place a thermometer into each one to check the initial temperature. Write this on the board once you have taken the starting temperature with your students. Leaving the thermometers in place, leave one plastic tub empty (apart from the can), fill one with ice, and fill the last with close to boiling water. Leave each set up for 5 minutes. When five minutes have passed, get your students to recheck the temperature and write the final temperature on the board. (You may also like to add thermometers into the tubs to show students what happens to the temperature of the surrounding ice/water.

Discuss the following with your students or ask them to write their responses in their student worksheet

What happened to the temperature of the can placed in the cold environment (with ice)? Why do you think this occurred?
What happened to the temperature of the can placed in the warm environment (with hot water)? Why do you think this occurred?
How did the temperature of the can placed by itself change after 5 minutes? Why did this happen?
What can you infer about the transfer of thermal energy in each scenario? How is heat being transferred from the surroundings to the soft drink or vice versa?

During this experiment, the can in the ice should decrease in temperature, the can in the hot water should increase in temperature, and the can by itself should stay roughly the same. This is because heat energy always travels from a hotter area to a colder area. This is the Second Law of Thermodynamics. Students can sometimes have a little bit of trouble understanding this flow; if you placed thermometers into the surrounding substance, students should hopefully see that the ice has increased in temperature as it has absorbed heat from the can (and the surrounding environment). The hot water has decreased in temperature as it has transferred heat to the can (and the surrounding environment).

Step 2

Watch the following video with your students, which describes thermal energy and temperature as a summation of what they have learned from the demonstration.

Thermal Energy, Heat and Temperature - Harmony Square (https://www.youtube.com/watch?v=K0SiEq3GAj0)

Ask your students to take note of the definitions of heat and temperature, what thermal energy has to do with the kinetic energy of particles and where heat travels from and to in a system in their student worksheet.

Find Out: What are the different methods of thermal energy transfer?

Step 1

Explain to your students that there are three ways that thermal energy can be transferred. Each of these methods relies on the properties of the substances and heat that we are dealing with.

You may like your students to brainstorm how this transfer of heat may occur. They might have heard of conduction and radiation and be able to describe these, but convection may be a new term to them.

Watch the following video with your students that outlines the methods of heat transfer. Invite your students to fill out the table below, which is on their student worksheet, as they watch.

GCSE Physics - Conduction, Convection and Radiation #5 - Cognito (https://www.youtube.com/watch?v=Eizsm5V8c_c)

Methods of heat transfer:

	Conduction	Convection	Radiation
What type of matter?
What's happening to the particles?
Example
Diagram
Interesting information

Step 2

Divide your students into groups of 3. Allocate each of the groups to investigate a different method of heat transfer. Students requiring support can be given conduction, and students needing extension can be allocated radiation. Encourage students to present their information in a format such as a poster or PowerPoint presentation to include diagrams to aid in their explanations. More information on the theory of this topic can be found in the Teacher Content Information.

Conduction	Convection	Radiation
What is conduction? What happens to the particles during conduction? What is an example of conduction occurring? What is thermal conductivity? What are examples of materials with high and low thermal conductivity? How can we use the conductivity properties of materials to our advantage?	What is convection? What happens to the particles in a liquid/gas during convection? How is it similar to conduction? What are some natural examples of convection in our environment? How can we use convection to our advantage for heat transfer?	What is radiation? How is it different from conduction and convection? What are some examples of heat transfer through radiation? How can we use radiation to our advantage for heat transfer?

Step 3

Join three groups together so each group can explain to the others the details of how their method of transfer works and all students can have a thorough overview.

Take Action: Applications of thermal energy transfer

Step 1

Explain to students that controlling the transfer of heat can help us in many respects. As well as enabling us to do critical everyday things such as cook and keep our food, homes and ourselves warm or cool, we can manipulate and control these processes to conserve heat energy.

Ask your students why it might be important to design objects and environments that conserve heat energy.

Suggested response: Heat is always looking to move from a hotter area to a cooler area. We want buildings to stay warm in winter and cool in summer. If we lose heat through the processes of radiation, conduction and convection, the more electricity we have to use to power air conditioners or heaters. This goes for other areas of life, too, such as appliances and different industries. (In the previous lessons in this unit, students learnt about energy efficiency in the production of electricity and how a big proportion of the chemical energy is lost as waste heat through the processes in the power plant. if you have taught this lesson, you might like to discuss this with your students to show the importance of conserving energy for efficiency)

This production of electricity, in order to keep the environments around us functioning appropriately, results in the production of greenhouse gases such as carbon dioxide that add to the greenhouse effect and climate change.

The CSIRO compiled data that shows the top two sources of our greenhouse gas emissions are

Energy (burning fossil fuels to produce electricity) - 33.6%
Stationary energy (including manufacturing, mining, residential and commercial fuel use) - 20.4%

The more we can conserve heat energy, the less extra energy and electricity we have to use, which saves greenhouse gas emissions as well as money!

Step 2

The question is, how can we use our understanding of how heat is transferred to conserve energy? Students will undertake a design task in order to redesign elements of their classroom environment to conserve heat energy. Depending on the time of year you are completing this lesson, you could frame it as trying to keep the classroom warm or keep it cool.

Divide students into pairs and encourage them to take a look around the classroom to identify where heat may be escaping or entering or where they can feel noticeable temperature differences. They could use thermometers to test the temperature in certain areas to gain further data to assist them. Encourage them to take notes about which method of heat transfer might be at play, remembering that heat energy will always move from the hottest area to the coldest area.

Examples that students might focus on include

Radiation

Sunlight through windows
Radiators or heaters,

Conduction

The walls, roof and doors can conduct heat energy into the room or out of it.
The type of floor covering can also conduct heat

Convection

Ceiling fan circulating air
Open windows to let air in (or out)
Heating or cooling vents

Some examples of redesigns students might tackle

Glazing windows
Blinds and shades

Insulation
Use of ceiling fans to circulate warm or cool air
Stopping air escaping through gaps
Flooring such as concrete can conduct heat and store it during the day and release it at night, carpet can insulate and reduce the amount of heat loss from the room through the floor

Students can choose their own aspect to investigate, or you can allocate to them. The goal is that all pairs do something different so students can come back together in the end with lots of different strategies to conserve heat in the classroom. Encourage students to observe, use the information they have learnt in this lesson and use the internet to help them in their designs

Students should address

What area of the room or type of heat issue they are working on
Why that aspect is less than ideal at the moment
How they can use the principles of heat transfer to fix this issue

Step 3

Invite students to present their designs to the rest of the class and encourage students to give feedback on others' work. What questions do they have for the presenting group? How do their strategies work together? What improvements could they suggest? Is there anything that could be implemented and improved easily? How could their strategy lessen the amount of electricity used in the classroom? What does this mean for the environment?

Reflection

What is your prediction about how one or more of these principles might be used to make homes comfortable without using fossil fuels to heat or cool them? What are your reasons for making this prediction?

What is a career or job that might focus on this area of improving the efficiency of buildings? Use the internet to help you research!

Energy: Thermal Energy and Methods of Transfer

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