A sinusoidal wave is propagating in negative x-direction in a string stretched along x-axis. A particle of string at `x=2` cm is found at its mean position and it is moving in positive y-direction at `t=1` s. the amplitude of the wave, the wavelength and the angular frequency of the wave are `0.1m,pi//4m` and `4pi rad//s`, respectively.
The instantaneous power transfer through `x=2 m` and `t=1.125 s` is

Options

A. `10 J//s`
B. `4pi//3 J//s`
C. `2pi//3 J//s`
D. 0

Answer

d

Explanation

Time period of oscillation `T=(2pi)/(omega)=(2pi)/(4pi)=(1)/(2)s`
Hence at `t=1.125 s`, that is, at `T//4` seconds after `t=1 s`, the particle is at extreme position. Hence, instantaneous power at `x=2` at `t=1.125 s` is zero.