Question

A uniform ring of mass m and radius R is rolling down a rough inclined plane which makes an angle 37° with the horizontal. If the friction is sufficient for pure rolling, then friction force on ring is

• A. $2mg/S$
• B. $\frac{mg}{5}$
• C. $\frac{3}{5}mg$
• D. $\frac{3}{10}mg$

Answer 1

The correct option is D $\frac{3}{10}mg$

$a=\frac{g\sin \theta }{m+\frac{l}{R^2}}$

$g\sin \theta =\frac{f}{m}=a$

$f=\frac{mg\sin \theta }{2}=\frac{3}{10}mg$