Question

A solid cylinder is sliding on a smooth horizontal surface with velocity v₀ without rotation. It enters on the rough surface. After that it has travelled some distance, select the correct statement:

(A) Friction force increases its translational kinetic energy. 

(B) Friction force increases its rotational kinetic energy. 

(C) Friction force increases its total mechanical energy. 

(D) Friction force increases its angular momentum about an axis passing through point of contact of the cylinder and the surface. 

Answer 1

Correct option: (B) Friction force increases its rotational kinetic energy.

Explanation:

The friction force will reduce v₀ , hence translational K.E. 

The friction force will increase ω

There is no torque about the line of contact, angular momentum will remain constant 

The frictional force will decrease the mechanical energy.