Two identical metal heat sinks are coated with different surface finishes. Each heat sink is initially at 80.0 °C and is allowed to cool for 10.0 minutes in the same room. The heat sinks are placed in positions A and B. The positions are exchanged in the second trial.
| Trial | Finish in position A | Final temperature in position A | Finish in position B | Final temperature in position B |
|---|---|---|---|---|
| 1 | matt black | 65.0 °C | polished silver | 71.0 °C |
| 2 | polished silver | 72.0 °C | matt black | 67.0 °C |
The heat sinks have the same mass and material, and all other conditions are kept the same.
Evaluate the conclusion that the matt black finish is a better emitter of infrared radiation than the polished silver finish.
96 exam-style questions on Edexcel GCSE Physics 5.3 Black body radiation, covering 5.3.1 Emission of radiation and temperature, 5.3.2 Radiation balance and constant temperature, and 5.3.3 The temperature of the Earth. Each one has a worked solution and a mark scheme showing where the marks go.