1. The problem statement, all variables and given/known data A pendulum is formed from a small ball of mass m on a string of length L. As the figure shows, a peg is height h \,=\:L/3 above the pendulum's lowest point. From what minimum angle theta must the pendulum be released in order for the ball to go over the top of the peg without the string going slack? Figure similar to this one on this site: http://www.ece.umd.edu/gradhandbook/physics1.gif [Broken] 2. Relevant equations Conservation of Energy: Ki+Ugi=Kf+Ugf Conservation of Momentum(because of peg and sting collision?): m1v1f+m2v2f = m1v1i+ m2v2i Force diagrams with tension: Lcos(theta)=Tension before peg Tension after=? 3. The attempt at a solution I'm am confused on how it all fits together as a system. I know it begins with potential energy and gains kinetic while swinging around the peg, and then potential again. I also know that the angle is going to correspond with the tension in the rope after swinging around the peg. I am unsure how to manipulate the equations, however..