1. The problem statement, all variables and given/known data A mass m = 5.500 kg is suspended from a string of length L = 1.570 m. It revolves in a horizontal circle (see Figure). The tangential speed of the mass is 2.874 m/s. What is the angle theta between the string and the vertical? PIC OF DIAGRAM: http://gyazo.com/fc4a226a7d1a3af6c298b9782de0d7fe 2. Relevant equations a = v2/r 3. The attempt at a solution I am totally stumped. I don't want anyone to give me an answer; all I want is a hint so I can get started on this problem (I assume I'll have to use sin / cos somewhere in the formula). Thanks in advance.