During a supernova, the iron core of a supermassive star collapses into a neutron star. Let the mass of the collapsing core be (3 x 10 ³⁰ kg), the initial radius is (6 x 10 ⁶ m), the final radius is (1 x 10 ⁴ m), and the initial rotation rate to be (1 rotation every 6 hours).

(a) What is the initial angular momentum of the core?

(b) What is the final rotation rate of the neutron star?

(c) From this new rotation rate, the neutron star is slowed to a halt in 3 billion years. What was the average torque on the neutron star during this time?