A boat at anchor is rocked by waves whose crests are `100 m` apart and whose speed is `25 m//s`. These waves reach the boat once every :

Options

A. 2500s
B. 75s
C. 4s
D. 0.25s

Answer

C

Explanation

Key Idea: The distance between the two consecutive crests in transverse wave motion is called wavelength.
The boat bounces up, ie, it travels from crest to the consecutive crest along wave motion.
Wavelength=distance between two consecutive crests
`i.e,=lambda=100m`
Velocity of wave=25m/s
Hence, time in one bounce of boat `t=(lambda)/(v)=(100)/(25)=4s`