You drop a ball from a height of 2.0 m and it bounces back to a height of 1.5 m (a) What fraction of its initial energy is lost during the bounce? (b) What is the ball’s speed just at it leaves the ground after the bounce?

Answer 1

(a) 1/4
(b) sqrt(3/4)*sqrt(2gH)
where H = 2.0 m
You could also write it as sqrt(2gH'), where H' = 1.5 m is the distance it rises after the first bounce