text: physics problem #1? please answer and show work... a ball on the end of a string is revolved at a uniform rate in a vertical circle of radius 72.0 cm. if it's speed is 4.00 m/s, and its mass is .300 kg, calculatethe tension in the string when the ball is (a) at the topof its path, and (b) at the bottom of its path. acceleration in a circular path=v^2/r v=tangential velocity of the mass r=radius of circle. here the mass is moving in circular  path in a vertical circle. hence the  gravity will come in to play. at the  top it will act against while at the  bottom it will add. acceleration on top  =v^2/r-g =[4^2/.72]-9.81 =22.22-9.81 =12.41m/sec^2 acceleration at bottom =v^2+g =[4^2/.72]+9.81 =22.22+9.81 =32.03 m/sec^2