waves moving in shallow water

[truewt]

Hi, just a really simple question I have.

Why do water waves travel slower in shallow water as compared to deeper water?

Also, as the water wave transit from deeper to shallower water, does the amplitude of the water wave change?

Thanks in advance.

[ZapperZ]

Please see this on-going thread that may have answers to your questions.

http://www.physicsforums.com/showthread.php?t=207783

Zz.

[truewt]

The thread does not answer why does waves (standing) move slower in shallower waters..

[russ_watters]

Friction and pressure effects from the rising wave are probably most of it. There is real mass transport in the shallows and the water has to be pushed uphill.

[DaveC426913]

This very principle is what causes breakers. Waves moving from deep water to shallow water (such as on a beach) will get slowed down by friction with the bottom. The surface part of the wave gets ahead of the deeper part and you get a breaker.

[rw0485]

because as the waves enter the shallower water, they change direction (or refract), thus slowing down