Question

A ball of mass 100g is dropped from a height of 1.25m above the ground surface.It rebounds to a height of 1.1m.Find the velocity of the ball just before impact

Answer 1

KE at ground= PE at top
1/2 m v^2=m*g*1.25
solve for velocity v. Note that the mass of the ball divides out.

Answer 2

V^2 = Vo^2+2g*h = 0+19.6*1.25 = 24.5
V = 4.95 m/s.