The earth rotates once around it spin axis in 23 h 56 min. If the radius of the earth is 6.4 X 10^6 m, calculate the speed of a person sitting at the equator

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?