Question

An anchored boat is rocked by waves whose crests are 100 m apart and whose velocity is 25 m/s. How often do the crest reach in boat?

• A. 0.35 seconds
• B. 4 seconds
• C. 75 seconds
• D. 2500 seconds

Answer 1

The correct option is B 4 seconds

The wavelenght of the boat is

$\lambda =100m$
And the velocity
$V=25m/s$
The velocity of a wave is also given as
$V=\gamma \lambda$
$V=\frac{25}{100}Hz$
Therefore, time
$T=1/f=1/\left(25/100\right)=100/25$
$T=4seconds$