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?
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a = v2/r
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.