# Bodies with potential energy

by aurao2003
Tags: bodies, energy, potential
 P: 126 1. The problem statement, all variables and given/known data Hi I am struggling with this question. It goes like this: A rubber ball is dropped on to flat ground from a height of 2m. (a) Calculate how long it takes for the ball to first hit the ground. (b)The ball loses 10% of its kinetic energy at each bounce. Calculate the time taken for the ball to come to rest. I am able to solve the first part using equation of motion. S=UT +0.5aT^2 I am not sure of the second part. 2. Relevant equations 3. The attempt at a solution
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P: 25,514
hi aurao2003!
 Quote by aurao2003 (b)The ball loses 10% of its kinetic energy at each bounce. Calculate the time taken for the ball to come to rest.
find the initial velocity, immediately after the first bounce, and use that to find the time between the first and second bounces

then do the same for all the bounces, and add them …
what do you get?
P: 126
 Quote by tiny-tim hi aurao2003! find the initial velocity, immediately after the first bounce, and use that to find the time between the first and second bounces then do the same for all the bounces, and add them … what do you get?
It seems to be forming a geometric progression. Is that right?

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