Angular Momentum (Problem 48)

A pulsar is a rapidly rotating neutron star. The Crab nebula pulsar in the constellation Taurus has a period of $33.5\times {10}^{-3}\text{s}$, radius 10.0 km, and mass $2.8\times {10}^{30}\text{kg}.$ The pulsar’s rotational period will increase over time due to the release of electromagnetic radiation, which doesn’t change its radius but reduces its rotational energy. (a) What is the angular momentum of the pulsar? (b) Suppose the angular velocity decreases at a rate of ${10}^{-14}\text{rad}\text{/}{\text{s}}^2$. What is the torque on the pulsar? Select the answer to part (a).