1. The problem statement, all variables and given/known data A pendulum is made of a rigid rod (mass m, length l) and a small bob of mass M attached at one end. The rod is pivoted on the other end. What should be the minimum speed of the bob at its lowest point so that the pendulum completes a full circle? 2. Relevant equations anything that'll work 3. The attempt at a solution I thought of finding the energy of the system when the bob is at the highest position. It came as E=(M+m/4)v21/2 where v1 is the velocity of the bob at topmost position. Then to get the energy at the bottom position, and then equating the two, this is what I get: (2M+m)gl + (M+m/4)v21/2 = (M+m/4)v22/2 , where v2 is the velocity of the bob at the bottom position But then what?