For the following system shown assume that pulley is frictionless, string is massless (m remains on M),
Q. The force on the ceiling is

Options

A. `((M+m)mg)/(2M+m)`
B. `((6M+5m)mg)/(M+m)`
C. `((M+m)mg)/(M+m)`
D. `((6M+5m)Mg)/(2M+m)`

Answer

D

Explanation

`T-mg=M(mg)/(2M+m)` for A block
`T=Mg+(Mmg)/(2M+m)`
For pulley
`P=2T+Mg`
`=2Mg+(2Mmg)/(2M+m)+Mg=(6M+3m+2m)/(2M+m)`Mg`
`P=((6M+5m)/(2M+m))Mg`