A wave motion has the function `y=a_0sin(omegat-kx)`. The graph in figure shows how the displacement y at a fixed point varies with time t. Which one of the labelled points Shows a displacement equal to that at the position `x=(pi)/(2k)` at time `t=0`?

Options

A. P
B. Q
C. R
D. S

Answer

B

Explanation

At `t=0` and `x=(pi)/(2k)` The displacement
`y=a_0sin(omegat-kxx(pi)/(2x))=-a_0sin(pi)/(2)=-a_0`
From graph. Point of maximum displacement `(a_0)` in negative direction is Q.