A smooth sphere A is moving on a frictionless horizontal plane with angular speed `omega` and centre of mass velocity `upsilon`. It collides elastically and head on with an identical sphere B at rest. Neglect friction everywhere. After the collision, their angular speeds are `omega_A and omega_B` respectively. Then

Options

A. `omega_(A) lt omega_(B)`
B. `omega_(A) = omega_(B)`
C. `omega_(A) = omega`
D. `omega_(B) = omega`

Answer

C

Explanation

As the spheres are smooth, there will be no transfer of angular momentum. Thus, A, after collision, will remain with its initial angular momentum.