A ball is dropped from a height of 20 m. You can use the relation between the work done by gravity and the change in the ball's kinetic energy to determine the speed of the ball at any point in its free fall. The speed of the ball when it hits the ground =

1 answer

(1/2) m v^2 = m g h
so
v = sqrt (2 g h)

if I call g = 9.81
v = 19.8 m/s