A 3.8 kg ball is swung in a horizontal circle at the end of a 1.5 meter rope. If the tension in the rope is kept constant at 79 N, what is the period of rotation, T?

Answer 1

Well, ignoring gravity (gravity makes the ball swing downward, the rope makes an angle, which changes the radius of rotation), then

tension= massball*v^2/r=m(2PIr/T)^2 /r

do the algebra, and solve for Period T.