A designer is choosing a surface finish for a panel that will be exposed to sunlight to heat water as quickly as possible.
Two metal panels are identical apart from their surface finish. They start at the same temperature and are exposed to the same sunlight for the same length of time.
| Surface finish | Temperature rise in ∘C^{\circ}\text{C}∘C |
|---|---|
| matt black | 18 |
| shiny silver | 7 |
Give the finish the designer should choose.
Explain your choice in (a) in terms of radiation.
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.