1. The problem statement, all variables and given/known data So I am jumping on a trampoline and need to look at the different systems and which ones are conserving energy and which ones are not conserving energy. Time-initial= when I am at the lowest point of the trampoline, and Time-final= when I am 1/2 on my way down. Systems : me trampoline me+earth me+ trampoline 2. Relevant equations Work= difference in energy 3. The attempt at a solution As me as the system I do not conserve energy because I change potential energy. Trampoline changes potential so it also does not conserve energy Me and Tramp would be energy conserved because there is no outside force acting on the system. Me + earth would be energy not conserved because I change energy causing the whole system to change. So where I've gone wrong and not sure where.