A thin circular ring and a solid disc, each of mass M and radius R, are mounted separately on identical friction-less bearings so that they can rotate about their central symmetry axes.
(a) Calculate the ratio of the moment of inertia of the ring to that of the disc about the common axis.
(b) Using the result of part (a), explain physically why the two bodies differ in their resistance to rotational motion.
(c) If the same constant torque is applied to both bodies for the same time interval, which one attains the greater angular speed? Give reasons for your answer.