1. The problem statement, all variables and given/known data A mass m = 16.0 kg is attached to the lower end of a massless string of length L = 63.0 cm. The upper end of the string is held fixed. Suppose that the mass moves in a circle at constant speed, and that the string makes an angle theta = 17o with the vertical, as shown in the figure. How long does it take the mass to make one complete revolution? 2. Relevant equations T = 2 pi r / v F = m a Ac = v^2 / r 3. The attempt at a solution m = 16 L = 0.62 m θ = 17 Drew a FBD... It shows mg acting down upon the object, and T diagonally up. Fx = m * ac T sin theta = m ac T sin theta = m * v^2/r T sin theta = m * v^2/ L sin theta Fy = m * ac T cos theta - mg = 0 T cos theta = mg T = mg /cos theta Use the above and sub it in.. (mg/cos theta) sin theta = m (v^2) / L sin theta √ ((( L (sin(theta))^2) g sin(theta))) / cos theta ) = V V = (sqrt( (.63 (sin^2(17)) (9.8) sin(17) )/ cos(17))) Use formula... T = 2pi r / v (2pi(0.63*sin(17)))/(sqrt( (.63 (sin^2(17)) (9.8) sin(17) )/ cos(17))) I get.. 2.88 seconds. Where did I go wrong?? Thanks for your time!