Everyone I know is having problems with this question: 3. [PSE6 6.P.011.] A 3.85 kg object is attached to a vertical rod by two strings as in Figure P6.11. The object rotates in a horizontal circle at constant speed 7.30 m/s. Figure P6.11 (a) Find the tension in the upper string. N (b) Find the tension in the lower string. N http://www.webassign.net/pse/p6-11.gif for the figure I've tried using various force equations, only to be wrong. Does anybody know how to do this problem??