A disc is given an initial angular velocity `omega_(0)` and placed on a rough horizontal surface as shown Fig. The quantities which will not depend on the coefficient of friction is/are

Options

A. the time until rolling begins
B. the displacement of the disc until rolling begins
C. the velocity when rolling begins
D. the work done by the force of friction

Answer

C, D

Explanation

The velocity of the disc when rolling begins can be obtained using the conservation of angular momentum principle about the point through which the friction force acts. So, the coefficient of friction has o bearing on the final velocity. The work done by the force of friction will simply be changed to kinetic energy.