Question

A solid sphere is in pure rolling motion on an inclined surface having inclination $\theta$

• A. frictional force acting on sphere is $f=\mu mg\cos \theta$
• B. f is dissipative force
• C. friction will increase its angular velocity and decrease its linear velocity
• D. If $\theta$ decreases, friction will decrease

Answer 1

Answer: (C), (D)

In case of pure rolling,
$f=\frac{mg\sin \theta }{1+\frac{m{R}^2}{I}}\text{ (upwards) }$
$\therefore f\propto \sin \theta$
Therefore, as 0 decreases force of friction will also decrease.