A 0.57 kg rubber ball has a speed of 2.2 m/s at point A and kinetic energy 8.0 J at point
B. Find
a) the ball’s kinetic energy at A.
Answer in units of J.

b) the ball’s speed at B.
Answer in units of m/s.

c) the total work done on the ball as it moves
from A to B.
Answer in units of J.

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?