posted by Will
When water waves travel, the water particles ___?
1. move with the wave and energy is not propagated
2. vibrate in the direction of wave motion and only energy is propagated
3. move with the wave and energy is propagated
4. vibrate perpendicular to the wave motion, and only energy is propagated
Well, I guess number 4 is what they want but none are correct.
In a deep water wave (water depth greater than half wavelength) the particles go around in a circle in place, up on the wave front, forward on the crest, down on the back , back in the trough for a net displacement of zero. That is sort of a vibration. As the wave enters shallow water the motion becomes more elliptical and eventually is just back and forth. Meanwhile the wave is slowed down so gets shorter and steeper.