1
									2				3
4
			5								6
								7
8																			9
									10
		11																			12
					13
14
			15					16
													17			18
											19
														20

Across 2. The sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listener 7. An increase in the measured frequency of light from an approaching source 8. The distance from the midpoint to the maximum (crest) of wave, or equivalently, from the midpoint to the minimum (trough) 10. A decrease in the measured frequency of light from a receding source 11. One of the places where the wave is lowest. 13. A wave in which the vibration is in the same direction as that in which the wave is traveling, rather than at right angles to it 14. A curve whose shape represents the crest and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt 15. A wave with vibration at right angles to the direction the wave is traveling 18. The SI unit of frequency 19. The number of events per time; measured in hertz. Inverse of period 20. The distance from the top of the crest of a wave to the top of the following crest, or equivalently, the distance successive identical parts of the wave

Down 1. Addition of two or more waves when wave crests overlap to produce a resulting wave of increased amplitude 3. One of the places in a wave where the wave is highest or the disturbance is greatest 4. Term applied to two or more waves whose crests and troughs arrive at a place at the same time, so that their effects reinforce each other 5. The change in frequency of a wave due to the motion of the source of the reciever 6. The time required for a pendulum to make one to-and-fro swing 9. The V-shaped wave produced by an object moving on a liquid surface faster than the wave speed 12. Any part of a standing wave that remains stationary 16. An oscillation, or repeating back-and-forth motion, about an equilibrium position 17. A wiggle in space and time