1. The problem statement, all variables and given/known data You've got two masses, m1 and m2, hanging from opposite ends of a rope that goes over a pulley with radius R. Both the masses are suspended by the rope alone and the pulley is on a frictionless peg. M2 moves down by x2 meters in 5 seconds. I believe that's all the variables we were given - m1, m2, radius R, and 2 meters in 5 seconds. EDIT: The pulley doesn't slip. Now find the accelleration of m1, the tensions of the rope on each side of the pulley, the angular velocity of the pulley, and the inertia of the pulley. 2. Relevant equations 3. The attempt at a solution I have no idea how to do this without being given the mass of the pulley or its inertia. Started out with m1gx + m2gx = (1/2)m1v^2 + (1/2)m2v^2 + (1/2)I(V/R)^2 + m1g*2x.