1. Starter
Explain why the following items are made with the surfaces shown.
What colour would you make something if you wanted it to absorb heat quickly.
Back of a refrigerator
Car radiator

2. Define perfect black body radiation Describe thermal equilibrium
Learning Objectives
By the end of this lesson you should be able to…
Define perfect black body radiation
Describe thermal equilibrium
Explain that all bodies emit and absorb infra-red radiation and how the amount of IR radiated is affected by temperature.
Investigate how Infra-red radiation absorption differs between different surfaces.

3. Investigating Infra-Red radiation
Follow the instructions on the sheet to investigate how different surface emit Infra-red radiation.

4. Rate of energy transfer
How can you calculate the rate of energy transfer from your graph.
What do you notice about the rate of energy transfer as the temperature changes?
Why do you think this is?

5. Black body radiation
A perfect black body absorbs all the Infra-Red radiation on it and does not reflect or transmit any radiation.
As a good absorber is also a good emitter of Infra-Red radiation a black body will also be the best emitter of radiation.

6. Homework
Answer all the questions to practice exam technique for practical questions.
Next lesson –ICT
Bring headphones please.

7. What are these?
Which one would it be good to paint black? Explain your answer.
Left picture – solar photovoltaic cells converting solar energy into electrical energy.
Right picutre – solar panels – heating water using solar IR energy.

8. How well are we doing now?
..\9. Infra Red Radiation\Ir radiation AfL questions.pptx
Can do this now or at start of next lesson.