In the figure, the pulley P moves to the right with a constant speed `v_(0)`. If the velocity of B is v in downward direction, find the velocity of A.

Explanation

Let B moves downward by y, the pulley moves to right in time t, a distance `v_(0)` t, the block will move to right by x.
`x=v_(0)t+y`
`(dx)/(dt)=v_(0)+(dy)/(dt)`