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 as well as direction
• B. constant in direction
• C. constant in magnitude
• D. constant

Answer 1

Answer: (A)

The circular disc of radius $R$ rolls without slipping. Its centre of mass is $C$ and $P$ is point where body is in contact with the surface at any instant. At this instant, each particle of body is moving at right angles to the line which joins the particle with point $P$ with velocity proportional to distance. In other words the combined translational and rotational motion is equal to pure rotation and body moves constant in magnitude as well as direction.