r3 central force* A particle of mass 50 g moves under an attractive central force of magnitude 4r3 dynes. The angular momentum is equal to 1000 g· cm2/s.
(a) Find the effective potential energy.
(b) Indicate on a sketch of the effective potential the total energy for circular motion.
(c) The radius of the particle's orbit varies between r0 and 2r0. Find r0.