Question

A ball is dropped from a height of 20 m and rebounds with a velocity which is 3/4 of the velocity with which it hits the ground.what is the time interval between the first and second bounces?

Answer 1

the velocity with which the ball reaches the ground is given by root over to 2GH where H is the height from which the ball is dropped. this comes out to be 20 metre per second. Now, after it touches the ground it rebounds with 3/4th of its velocity on reaching the ground. this comes out to be 15 metre per second and by using V is equal to U +AT( take A as acceleration due to gravity 10m/s^2) where V is the final velocity U is the initial velocity and T time. As V is zero and U is 15 we get The as 1.5seconds