Question

A drum of radius $R$ and mass $M$, rolls down without slipping along an inclined plane of angle $\theta$ The frictional force

• A. converts translational energy to rotational energy
• B. dissipates energy as heat
• C. decreases the rotational motion
• D. decreases the rotational and translational motion

Answer 1

Answer: (A)

converts translational energy to rotational energy

Answer 2

When a body rolls down without slipping along an inclined plane of inclination $\theta$, it rotates about a horizontal axis through its centre of mass and also its centre of mass moves. Therefore, rolling motion may be regarded as a rotational motion about an axis through its centre of mass plus a translational motion of the centre of mass. As it rolls down, it suffers loss in gravitational potential energy provided translational energy due to frictional force is converted into rotational energy.