1. The problem statement, all variables and given/known data A ball of mass m on the end of a string is released from rest when the string is held horizontal eg: 0----- Prove that as the ball moves through the lowest point in its swing the string has a magnitude equal to three times the weight of the ball. 2. Relevant equations Fc = mv^2/r Weight = mg 3. The attempt at a solution Because its motion in a vertical circular plane, I thought that mv^2/r would be needed, obviously the equation would end up something like xxxxxx = 3mg But I'm not sure how or why that would happen? Any thoughts?