A disc rotating about its axis with angular speed \omega_{0} is placed lightly (without any translational push) on a perfectly frictionless table. The radius of the disc is R. What are the linear velocities of the points A, B and C on the disc shown in Figure. Will the disc roll in the direction indicated?
A disc rotating about its axis with angular speed \omega_{0} is placed lightly (without any translational push) on a perfectly frictionless table. The radius of the disc is R. What are the linear velocities of the points A, B and C on the disc shown in Figure. Will the disc roll in the direction indicated?

Solution:

The respective linear velocities are :

For point A, v_{A}=r \omega_{0}

For point B, v_{B}=r \omega_{0}

both in the direction of arrow

For point C, v_{c}=(R / 2) \omega_{0} in the same direction as that of v_{A}

To begin with, the disc receives no tangential push in the initial state. Second, the only source of tangential force was friction, but this is no longer the case because the surface is frictionless. As a result, the disc is unable to go forward.