Better approximation! There exists an item in nature that is extraordinarily spherical, where the approximation of a uniform sphere is astonishingly close. A pulsar is a rotating neutron star, the remnant of a supernova of a star between six and eight solar masses. A typical pulsar rotates at a rate of 600 rpm, has an average mass of twice that of the Sun, and is only 20 km in diameter, or about as big across as Washington, D.C. 

(a) What is the rotational kinetic energy of an average pulsar? 

(b) What is the corresponding angular momentum?