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Lucyc2008
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Homework Statement
A 3.20kg rubber ball drops from a height of 4.80m to the ground a bounces back to a height of 2.70m
a) how much potential energy does the ball lose on the trip down?
b) how much energy does the ball regain on the trip back up?
c) what is the net loss of potential energy?
Homework Equations
Ep = mgh
The Attempt at a Solution
I got the question "correct" a) (3.20) x (9.80) x (4.80) = 151J b) (3.20) x (9.80) x (2.70) = 84.7J C) 151 - 84.7 = 66.3J but when studying for my test I found a completely different way of solving it by subtracting Ep2 (84.7) from Ep1 (151) so answer a) would be Ep lost = 67 instead. What is the correct way of solving this equation?. Attached is the second way of solving. The first way makes more sense in my mind because there is no height as the ball hits the ground so Ep = 0.
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