A ball is thrown vertically down from a height of 40m from the ground with an initial velocity 'v'. The ball hits the ground, loses one-third of its total mechanical energy and rebuounds back to the same height. If the acceleration due to gravity is 10 ms^(-2), the value of 'v' is

A ball is thrown vertically down from a height of 40m from the ground

1.	A ball is thrown vertically down from a height of 40m from the ground with an initial velocity 'v'. The ball hits the ground, loses one-third of its total mechanical energy and rebuounds back to the same height. If the acceleration due to gravity is 10 ms^(-2), the value of 'v' is
Answer» `5MS^(-1)` `10 ms^(-1)` `15 ms^(-1)` `20 ms^(-1)` ANSWER :D