A hollow, thin-walled sphere of mass 13.0kg and diameter 45.0 cm is rotating about an axle through its center. The angle (in radians) through which it turns as a function of time (in seconds) is given by theta(t)=At^2+Bt^4, where A has numerical value 1.20 and B has numerical value 1.60.
(A) What are the units of the constants A?
(B) What are the units of the constants B?
(C) At the time 4.00s, find the angular momentum of the sphere.
(D) At the time 4.00 s, find the net torque on the sphere.