Question

A solid uniform disc of mass m rolls without slipping down an inclined plane with an acceleration a. The frictional force on the disc due to surface of the plane is

• A. $2ma$
• B. $\frac{3}{2}ma$
• C. $ma$
• D. $\frac{1}{2}ma$

Answer 1

The correct option is D $\frac{1}{2}ma$


$\tau =I_0\alpha$
$fR=\frac{1}{2}m{R}^2\alpha$
$f=\frac{1}{2}ma$ $(\because a=\alpha R)$