A volunteer is holding a rapidly rotating horizontal bicycle wheel with two handles as shown. The volunteer rotates the bicycle
wheel so that the upper hand holding it becomes the lower hand.
What effect does this have?

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?