A rubber ball is dropped from a height of 2 metres. To what height will it rise if there is no loss of energy/velocity after rebounding? (1) 4 metres (2) 3 metres (3) 2 metres (4) 1 metre
(3) 2 metres Explanation: The potential energy of a body when raised through height h is given by mgh. Each time, a normal rubber ball hits the floor, it loses one-fifth of its total energy and the rebound height is proportional to energy, so each bounce will rebound to four-fifth of the previous bounce.