Question: An object that is 3.0kg is swinging from a 2.0m string in a vertical circle. If the frequency of motion the is 6Hz. What is tension of the string, at the top of the circle and the bottom? Answer: (top part) T = 1/f = 1/(6) = 0.167, Fc = 4π^2mr/T^2 = (4.0)(π)^2 (3.0)(2.0)/ (0.167)^2 = 8527.3N, Fg = mg = (3.0)(9.81) = 29N, Fc = FT+ Fg, FT = Fc - Fg = 8527.3 - 29N = 8497.9 N = 8.5 times 10^3N (bottom part) Fc = FT - Fg, T = 1/f = 1/(6) = 0.167, Fc = 4π^2mr/T^2 = (4.0)(π)^2 (3.0)(2.0)/ (0.167)^2 = 8527.3N, Fg = mg = (3.0)(9.81) = 29N, FT = Fc + Fg = 8527.3N + 29N = 8556.3 = 8.6 times 10^3N
