A lightweight rigid rod of negligible mass connects two small solid spheres, each of mass m=0.40kg and radius r=0.030m, whose centers are separated by L=0.60m. The rod–sphere system rotates about an axis that is perpendicular to the rod and passes through a point on the rod located 0.15m from the center of one sphere.
(a) Treating each sphere as a solid sphere, calculate the rotational inertia of a single sphere about the given axis.
(b) Determine the total rotational inertia of the entire rod–sphere system about the stated axis.
(c) The system is set spinning from rest to an angular speed of 20rads−1. Calculate the rotational kinetic energy after the spin-up.