(II) Suppose our Sun eventually collapses into a white dwarf, losing about half its mass in the process, and winding up with a radius 1.0% of its existing radius. Assuming the lost mass carries away no angular momentum, (a) what would the Sun's new rotation rate be? Take the Sun's current period to be about 30 days, (b) What would be its final kinetic energy in terms of its initial kinetic energy of today?

Step-by-step solution

Step 1 of 4</p>

The initial mass of the Sun is M and the Radius is R

The initial period of rotation

After this time, the Sun collapses into a white dwarf.

The final mass of the Sun is anc Radius is 0.01R.

Final period of rotation

As no external force is applied, angular momentum of the Sun remains conserved.

Step 2 of 4</p>

From the principle of conservation of angular momentum