Across
- 4. the energy used by a 1kW electrical appliance in 1 hour
- 5. line which is perpendicular to a surface
- 6. change in velocity per unit time
- 7. distance travelled per unit time
- 8. charge passing a point per unit time
- 11. ratio of the speed at which the galaxy is moving away from the Earth to its distance from the Earth
- 12. line through the optical centre of a lens at right angles to the lens
- 13. distance between the centre of the lens and the principal focus
- 14. mass × velocity
- 16. work done by a unit charge passing through a component
Down
- 1. force per unit extension
- 2. force × time for which force acts
- 3. time taken for half the nuclei of that isotope in any sample to decay
- 9. sound with a frequency higher than 20 kHz
- 10. mass per unit volume
- 15. force × perpendicular distance from the pivot