The equation of a plane progressive wave is given by y=5 cos π(200 t-x/150) where x and y are in cm and t is in second. The velocity of the wave is…

The equation of a plane progressive wave is given by $\displaystyle y=5 \cos \pi\left(200 t-\frac{x}{150}\right)$ where $\displaystyle x$ and $\displaystyle y$ are in cm and $\displaystyle t$ is in second. The velocity of the wave is $\displaystyle \_\_\_\_$ m/s.