A heavy mass M resting on the ground is connected to a lighter mass m through a light inextensible string passing over an ideal pulley. The string connected to mass M is loose. Let lighter mass m be allowed to fall freely through a height h such that the string becomes taut. If t is the time from this instant onward when the heavier mass again makes contact with the ground and `Delta E` is change in kinetic energy then

Options

A. `t=(2m)/(M+m)sqrt((2h)/(g))`
B. `t=(2m)/(M-m)sqrt((2h)/(g))`
C. `Delta E = - ((M m)/(m+m))gh`
D. `Delta E =- Mgh`

Answer

B, C