Question

A star of mass 4 times the solar mass and radius 10⁸ km rotates about its axis with an angular speed of 10^-4 rad s^-1. When the star collapses to a radius at 10⁵ km, then its angular speed is

(Take, solar mass = 1.99 x 10³⁰ kg)

(a) 10 rad s⁻¹

(b) 0.1 rad s⁻¹

(c) 10² rad s⁻¹

(d) 10⁻² rad s^-1

Answer 1

Answer is : (d) 10⁻² rad s^-1

As total momentum remains conserved,