1. The problem statement, all variables and given/known data https://int.erlace.com/uploads/teacher/1533/images/3modifiedatwood(1).jpg [Broken] Ignore friction and the the rope and the pulley and the rope have negligible mass. When the hanging block has descended a distance , how much work has the gravitational force by the earth done on the system? That work went into the kinetic energy of the masses. What fraction of that kinetic energy went into the motion of the hanging block? Suppose now there's a coefficient of kinetic friction between and the table surface. Find the speed of the masses when has descended that distance . 2. Relevant equations 3. The attempt at a solution 1. I figured the work done was equal to change in potential energy, so 2. I'm not sure how to go about this one. I tried to take what I found for the work done and relate it the kinetic energy of the masses, so something like , but I don't know if this would help, or if it is right at all. 3. Not sure. I derived an expression for acceleration of the system, and again I don't know if it would help. Thanks.