Question

As water waves from the ocean approach a shallow beach, their wavelengths become shorter. Explain why.

v=fwavelength, frequency remains constant & velocity & wavelength decrease or increase w/ water depth.

Is that a reasonable answer or are they looking for something else?
Thanks :)

Answer 1

The speed is slower, but the same number have to pass you in a minute if you are sitting there watching. There is no storage closet for the waves.
In other words the same answer as for your earlier question.
L = v T
T is constant
v, the speed, decrease
so
L decreases
(it gets shorter and steeper and breeaks)

In deep water
v = constant * sqrt L
in shallow water
v = constant * sqrt (depth)

shallow water starts when the depth is about half the deep water wavelength. (It scrapes the bottom :)

Answer 2

Ok, that makes sense, thank you :)