Question

A girl floating in the ocean and watches 12 wave crests pass her in 46 s. Calculate the wave frequency and period?

Answer 1

The frequency of a wave is the number of crests passing a point in one second.
If in t=46 s the number of crests passing a certain point is 12, the frequency will be

`f= (N)/(t) = (12)/(46 s) =0.26 Hz`
So, 0.26 crests pass a certain point in 1 s.

The period of a wave is the time interval between two consecutive crests, and it is equal to the inverse of the frequency:

`T= (1)/(f)= (1)/(0.26 Hz)=3.85 s`
It means that the girl sees 1 wave crest passing every 3.85 s in a certain point.