A spacecraft engineer tests a flat panel coated with a matt white material. A lamp produces parallel rays that travel vertically down towards the panel. Camera sensors are moved around above the panel and detect reflected light over a wide range of positions.
The table shows measurements for rays striking four microscopic regions of the panel.
| region | direction of local normal from upward vertical | angle of incidence | angle of reflection | direction of reflected ray from upward vertical |
|---|---|---|---|---|
| A | 3° left | 3° | 3° | 6° left |
| B | 12° right | 12° | 12° | 24° right |
| C | 20° left | 20° | 20° | 40° left |
| D | 28° right | 28° | 28° | 56° right |
Explain how the measurements account for camera sensors detecting reflected light over a wide range of positions.
The engineer considers replacing the matt coating with a smooth, polished coating.
Explain how this would affect the range of camera positions from which bright reflected light is detected.
93 exam-style questions on Edexcel GCSE Physics 5.1 Reflection, refraction and lenses, covering 5.1.1 Reflection, refraction and total internal reflection, 5.1.2 Specular and diffuse reflection, 5.1.3 Colour of light: absorption and filters, 5.1.4 Lenses: power, focal length and shape, 5.1.5 Ray diagrams for converging and diverging lenses, and 5.1.6 Real and virtual images. Each one has a worked solution and a mark scheme showing where the marks go.