Question

A boat at anchor is rocked by waves whose crests are $ 100\, m $ apart and velocity is $ 25\, m/s $ . The boat bounces up once in every :

• A. $ 2500\,s $
• B. $ 75\,s $
• C. $ 4\,s $
• D. $ 0.25\,s $

Answer 1

Answer: (C)

The distance between the two consecutive crests in transverse wave motion is called wavelength.
The boat bounces up, i.e., it travels from crest to the consecutive crest along wave motion.
Wavelength = distance between two
consecutive crests
i.e., $λ = 100\, m$
Velocity of wave, $v =25\,m/s$
Hence, time in one bounce of boat
$t = \frac{λ}{v} = \frac{ 100}{25} = 4\, s$