A ball of mass m is projected vertically downwards with speed v from a certain height and rebounds from the ground back to the same height.
(1) The collision between the ball and the ground is not perfectly elastic.
(2) The loss in energy of the ball in the collision is 1/2 mv^2.
(3) If the ball is progected vertically upwards from the same height with the same speed, it would rebound to a greater height.
Ans is (1) and (2)
Explain briefly. thx