A thin circular ring and a solid disc each have mass 2kg and radius 0.50m. Both rotate separately about their symmetry axes with the same angular speed 10rads−1. Which statement about their rotational kinetic energies is correct?
a) The disc has twice the rotational kinetic energy of the ring.
b) The disc has four times the rotational kinetic energy of the ring.
c) The ring has twice the rotational kinetic energy of the disc.
d) Both have the same rotational kinetic energy.