Two surfaces at the same temperature are tested with an infrared detector at a fixed distance. The table shows the readings after background has been subtracted.
| Surface | Reading 1 | Reading 2 | Reading 3 |
|---|---|---|---|
| P | 18 | 20 | 19 |
| Q | 9 | 10 | 11 |
By approximately what percentage is the mean reading for P greater than the mean reading for Q?
47%47\%47%
90%90\%90%
53%53\%53%
190%190\%190%
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.