A chamber uses an ultraviolet lamp to treat the outer surfaces of reusable protective helmets as they pass through on a conveyor.
| Operating quantity | Value |
|---|---|
| Conveyor length illuminated by the lamp | 2.4 m |
| Average speed of the helmets | 0.12 m/s |
| Minimum ultraviolet exposure time | 15 s |
Determine whether the helmets receive enough ultraviolet exposure for their surfaces to be disinfected.
Use the equation
average speed=distance÷time\text{average speed} = \text{distance} \div \text{time}average speed=distance÷time
104 exam-style questions on Edexcel GCSE Physics 5.4 Uses and dangers of EM radiation, covering 5.4.1 Dangers of electromagnetic radiation, 5.4.2 Uses of electromagnetic radiation, 5.4.3 Radio waves and oscillations in circuits, and 5.4.4 Changes in atoms and nuclei generating radiation. Each one has a worked solution and a mark scheme showing where the marks go.