Question

A solid cylinder of mass $m$ and radius $r$ is rolling on a rough inclined plane of inclination $\theta$. The coefficient of friction between the cylinder and incline is $\mu$. Then:

• A. frictional force is always $\mu mg\cos \theta$
• B. friction is a dissipative force.
• C. by decreasing $\theta$, frictional force decreases.
• D. friction opposes translation and supports rotation.

Answer 1

Answer: (C), (D)

The correct options are
C by decreasing $\theta$, frictional force decreases.
D friction opposes translation and supports rotation.

From the diagram we observe $f$ opposes translational and supports rotational

Also $mgsin\theta =f$

$\Rightarrow f\propto \sin \theta$

Thus if we reduce $\theta$

$f$ will be decreased