A wave representing by the equation `y = A cos(kx - omegat)` is suerposed with another wave to form a stationary wave such that point `x = 0` is a node. The equation for the other wave is

Options

A. `a sin(kx + omega t)`
B. `a sin(kx - omega t)`
C. `- a sin(kx + omega t)`
D. `- a sin(kx - omega t)`

Answer

C

Explanation

Stationary wave is produced when two waves travel in opposite directions. Now,
`y= a cos(kx - omegat) - a cos(kx + omega t)`
`y = 2a sin kx sin omega t` is equation of stationary wave which gives a node at `x = 0`.