Consider a uniform disc of mass `m`, radius `r` rolling without slipping on a rough surface with linear acceleration `a` and angular acceleration `alpha` due to an external force F as shown in the figure coefficient of friction is `mu`.
Q. The work done by the frictional force at the instant of pure rolling is

Options

A. `(mumgat^(2))/(2)`
B. `mumgat^(2))`
C. `mumg(at^(2))/(alpha)`
D. zero

Explanation

Bottommost point where friction actually acts is at rest.