In `Q.137`, if we hang a body of mass `m` from the cord, the tangential acceleration of the disc is :

Options

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

Answer

C

Explanation

( c) From above problem, `T = (Ma)/(2)`
Now `mg - T ma` or `mg - M (a)/(2) = ma`
or `mg = (m + (M)/(2)) a` or `a = (2 mg)/(M + 2 m)`.