An observer standing at the sea coast observes `54 waves` reaching the coast per minute. If the wavelength of a wave is `10 m`, its speed is :

Options

A. `90 m//s`
B. `90 cm//s`
C. `9 m//s`
D. `900 m//s`

Answer

C

Explanation

As frequency, `v = (54 "waves")/(60 s) = (9)/(10) Hz, lamda = 10 m, v = v lamda = ((9)/(10) xx 10) m//s = 9 m//s`.