posted by Hannah .
A ball is dropped from 27.0 ft above the ground. (a) Using energy considerations only, what
is the velocity of the ball just prior to it hitting the ground? (b) If the ball is thrown back up to
a ledge 15 m above the ground, what would be the velocity just as it reaches the ledge?
(1/2) m v^2 = m g h
v = sqrt(2gh)