Question

A circular disc of radius $R$ rolls without slipping along the horizontal surface with constant velocity $v_0$. We consider a point $A$ on the surface of the disc. Then, the acceleration of the point $A$ is

• A. constant in magnitude
• B. constant in direction
• C. constant in magnitude as well as direction
• D. None of the above

Answer 1

Answer: (C)

The circular disc of radius $R$ rolls without slipping, and its centre of mass is $C$. $P$ is that point where the body is in contact with the surface at any instant. At this instant each particle (body) is moving at right angles to the line which joints the particle with point $P$ with velocity proportional to distance.

Therefore, the combined translational and rotational motion gives pure rolling and body moves with constant velocity in magnitudes as well as in direction.