RP 10

Question 1

Describe how to investigate how much infrared radiation is radiated by different surfaces.

Answer 1

1. Fill Leslie’s cube with hot water.
2. Point infrared detector at each surface and record the infrared radiation emitted, at the same distance.

Question 2

What are the conclusions of the Leslie’s cube experiment?

Answer 2

Order of least to most infrared emitted:
- Shiny metallic
- White
- Shiny black
- Matt black

Question 3

Describe how to investigate how much infrared radiation is absorbed by different surfaces.

Answer 3

1. Set up infrared heater with two metal surfaces at each side, painted shiny black and matt black, with a drawing pin stuck on via vaseline.
2. Turn on the heater and record time for the vaseline to melt and the drawing pin to fall off, with a timer.

Question 4

What are the conclusions of the infrared heater experiment?

Answer 4

The drawing pin dropped from matt black surface first because matt black surfaces absorbed more infrared than shiny metallic surfaces.