Athin-walled, hollow sphere of mass m and radius r is free to rotate around a vertical shaft that passes through the center of the sphere. initially, the sphere is at rest. a small ball of clay of the same mass m moving horizontally at speed v grazes the surface of the sphere at its equator. after grazing the surface, the ball of clay is moving at speed v/2. what is the angular momentum of the ball of clay about the shaft before it grazes the surface? after it grazes the surface?

initial angular momentum is given as

final angular momentum is given as

Explanation:

Angular momentum of the ball about the axis of the thin walled sphere is given as

here we know that

before it grazes the surface the speed is "v" while after grazing the surface its speed is "v/2"

So we have

initial angular momentum is given as

final angular momentum is given as

the answer is kevlar

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.