Two simple harmonic motion are represented by equations
`y_(1) = 4 sin (10 t + phi)`
`y_(2) = 5 cos 10t`
What is the phase difference between their velocities ?

Options

A. `phi`
B. `- phi`
C. `(phi + (pi)/(2))`
D. `(phi - (pi)/(2))`

Answer

D

Explanation

`y_(1) = 4 sin (10t + phi)`
`y_(2) = 5 cos 10s`
`y_(1) = (dy_(1))/(dt) = 40cos (10t+ phi)`
`y_(2) =(dy_(2))/(dt) = - 50 sin(10t+ 50 cos (10t + pi//2)`
Phase diffarence between `v_(1) `and `v_(2) = (phi - (pi)/(2))`