# Physics question Energy Problems with a loss

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1. Feb 23, 2016

### Araiz

1. The problem statement, all variables and given/known data
This is a simple question but I can't seem to solve it( I don't know if this is advanced physics or not first time on this website, it said Work and that is part of this energy loss problem) here is the problem: What percentage of its gravitational potential energy does a squash ball lose if it falls from 3.0 m and returns to a height of .076 after bouncing once?

2. Relevant equations
(100-x)(Ek1 + Eg1)/100 = Ek2 + Eg2
Ek = 1/2mv²
Eg = mgh

3. The attempt at a solution
Honestly, my Teacher did not give any example on a question with no "x" variable like this one, so literally I had no clue on how to attempt this question.

2. Feb 23, 2016

### Staff: Mentor

Welcome to the PF.

You would just compare the E=mgh values of PE for the start and end positions of the ball. But what does "to a height of 0.076" mean? 0.076 meters, or 0.076*3.0 meters?

3. Feb 23, 2016

### Araiz

Thanks !

Its H1= 3.0 m and H2= .076, I know that for sure because, the ball is first at 3.0 M then it bounces and reaches a height of .076m. thats all i got from the question, oh and g= 9.80.

4. Feb 23, 2016

### Staff: Mentor

So all you have to do is calculate the two mgh values, and figure out what percentage of the original PE was lost in the bounce.