A 200g ball is dropped from a height of 20m , on impact on a ground, it loses 30j of energy. Calculate the height of a ball as reaches on its rebound. (G=10m/s2

Answer 1

energy before hit = m g h
= .2 * 10 * 20
= 40 J
energy after hit = 10 J

m g h = 10
2 h = 10
h = 5 meters

Answer 2

2* 10* 20=40

Mgh=10
2h = 10
h = 5