Question

An observer on the sea shore observes 54 waves reaching the coast per minute. If the wavelength is $10\text{m}$, the velocity of the waves is

• A. $9{\text{ms}}^{-1}$
• B. $54{\text{ms}}^{-1}$
• C. $18{\text{ms}}^{-1}$
• D. $36{\text{ms}}^{-1}$

Answer 1

The correct option is A $9{\text{ms}}^{-1}$

Given, $f=\frac{54}{60}=\frac{9}{10}\text{Hz}$
We know, $v=f\lambda =\frac{9}{10}\times 10=9{\text{ms}}^{-1}$