a ball is dropped from a height 20 m and rebounds with a velocity which is 3/4of the velocity w8th which it hits ground. What is the time interval between the first and second bounces
Answers
Answer:If the ball is dropped from height h above the ground, then it reaches the ground with speed begin mathsize 12px style v space equals space square root of 2 cross times g cross times h end root end style
if it rebounds with (3/4)th of its velocity, then time taken t to reach maximum height after first bounce is given by
t begin mathsize 12px style equals space fraction numerator 3 over 4 square root of 2 g h end root over denominator g end fraction space equals space 3 over 4 square root of fraction numerator 2 cross times h over denominator g end fraction end root space equals space 3 over 4 square root of fraction numerator 2 cross times 20 over denominator 10 end fraction end root space equals space 3 over 2 s end style
the ball will take same time to reach the ground just before second rebounce.
Hence the time interval between first and second rebounce is 3 seconds