The system shown in the figure is released from rest. At the instant when mass M has fallen through a distance h, the velocity of m will be

Options

A. `sqrt(2gh)`
B. `sqrt(2ghM)/(m)`
C. `sqrt((2gh(M-m))/(m+M))`
D. `sqrt((2gh(M+m))/(m-M))`

Answer

C

Explanation

(c ) From conservation of mechanical energy
`(M-m)gh=(1)/(2)(M+m)v^(2)`
`:. " " v=sqrt((2gh(M-m))/(m+M)`