1. The problem statement, all variables and given/known data A ring of mass M is hung from the ceiling. At the top of the ring are two smaller rings of mass m. There is no friction between the big and small rings. If two smaller rings slip down the big ring, for what value of m will the big ring move upward. A picture is attached to make the question clearer. 2. Relevant equations a = v(sqrt)/R 3. The attempt at a solution I just don't understand how do all the forces react to give rise to the upward motion of the big ring.