A uniform sphere of radius R rotates about a diameter with angular momentum of magnitude L.Under the action of internal forces the sphere collapses to a uniform sphere of radius R/2.The magnitude of its new angular momentum is:
A)L/4
B)L/2
C)L
D)2L
E)4L

Question

Quizplus · Accepted Answer

The angular momentum of a rotating object is conserved if no external torques act on it. Since the sphere collapses due to internal forces, its angular momentum remains the same, L.

A Uniform Sphere of Radius R Rotates About a Diameter