A solid cylinder of mass `m` is kept in balance on a fixed incline of angle `alpha=37^@` with the help of a thread fastened to its jacket. The cylinder does not slip.

What force `F` is reqired to kep the cylinder in balance when the thread is held vertically?

Options

A. `mg//2`
B. `3mg//4`
C. `3mg//8`
D. `5mg//8`

Answer

C

Explanation

Balancing torque about `C`

`Fr="fr"impliesf=F`
balancing force in the direction of incline
`Fsinalpha+f=mgsinalpha`
`impliesF(3/5)+F=mg(3/5)impliesF=(3mg)/8`