When a sound wave of frequency 300 Hz passes through a medium the maximum displacement of a particle of the medium is 0.1 cm . The maximum velocity of the particle is equal to

Options

A. `60 pi cms^-1`
B. `30 pi cms^-1`
C. `30 cm s^-1`
D. `60 cm s^-1`

Answer

A

Explanation

`a omega=0.1 times 2pi times 300=60 pi cms^-1`
For a wave travelling along positive x-axis
`y=a sin (omega t-k x)`
`=a sin (2pi n t-(2 pi x)/lamda)=0.2 sin 2 pi (6t- pi/60)`