stone tied to string whirled. Max string tension?? 1. The problem statement, all variables and given/known data A stone of mass m at the end of a string of length l is whirled in a vertical circle at a constant speed when will the tension in the string be maximum? 2. Relevant equations a) at the top of the circle b) halfway down from the top c) quarterway down from the top d) at the bottom of the circle 3. The attempt at a solution i know the answer, its obvious its the bottom of the circle due to force required to overcome the effect of gravity, but how can one prove it mathematically using the different physics phenomenon.