Turning Points in Physics Revision Crossword

3. Wave like oscillations that were thought to originate from every point along a wavefront according to Huygen's principle.
6. A device that uses thermionic emission and a high potential difference to produce an accelerate beam of electrons.
10. When a high frequency photon incident on a metal surface releases an electron.
11. The speed of light is ........... this means that it does not change speed regardless of the frame of reference.
12. The name of an experiment which was used as direct evidence for the relativistic variation of kinetic energy with speed.
13. A frame of reference in which Newton's 1st law is obeyed.

1. The mass of a body in motion.
2. An object moving relative to an observer appears shorter.
4. An observer moving at a constant speed relative to two events will observe a longer time than a stationary observer.
5. The ratio of charge to mass for a particle.
7. The time interval between two events as measured by an observer who is stationary in relation to those two events.
8. This piece of equipment was used by Michelson and Morley to show that the ether did not exist.
9. The kinetic energy gained by an electron after it has been accelerate through a potential difference of 1V.