A wave is represented by $y ( x , t ) = - A \cos ( \omega t - k x )$ . The direction the wave moves in is
A) the positive x direction.
B) the negative x direction.
C) the positive y direction.
D) the negative y direction.
E) none of the above.

Question

Quizplus · Accepted Answer

The wave equation $y(x, t) = -A \cos(\omega t - kx)$ indicates a wave moving in the positive x-direction because the argument of the cosine function is $\omega t - kx$, where a negative sign in front of $kx$ signifies movement in the positive x-direction.

A Wave Is Represented By y(x,t)=−Acos⁡(ωt−kx)y ( x , t ) = - A \cos ( \omega t - k x )y(x,t)=−Acos(ωt−kx)

A Wave Is Represented By $y ( x , t ) = - A \cos ( \omega t - k x )$