1. The problem statement, all variables and given/known data Basically, an ideal Atwood machine is released from rest (m1 != m2) and I have to find out how high the mass, say m1, bounces after an absolutely inelastic collision with the floor (no energy is lost). 2. Relevant equations Conservation of energy, Newtons equations. 3. The attempt at a solution Well, I can find the velocity of the system when it hits the ground in two ways, cons. of energy and by using Newtons II'nd law. The first one is preferred since it does not include time in it. Now, using this velocity I should be able to find how high the system bounces after the collision, but I'm a bit lost on that. Where look and how to do?