Two wires are tied to the 400 g sphere shown in figure. The sphere revolves in a horizontal circle at a constant speed of 8.30 m/s 1) What is the tension in the upper wire? 2) What is the tension in the lower wire? okay i know that m=.4 and v=8.3 i dont know r, which i thought that maybe i could find by doing the square root (1^2-.5^2) =.866 and then Force= m V^2 / R sooo.. (.4)(8.3^2)/(.866) = 31.819 . but i dont know where to go from there?