1. The problem statement, all variables and given/known data A 1.3kg stone is whirled in a vertical circle at the end of a 0.83m long string. The tension in the string at the top of the circle is 6.4N. What is the tension in the string when the stone is at the bottom of the circle? 2. Relevant equations Fc= mac W=|F||Δd|cosθ WALL= E2- E1 E= 1/2 mv2- mgh 3. The attempt at a solution I think I'd have to find the speed of the stone at the bottom of the circle first but I'm not sure how to start it.