Conical Pendulum

A conical pendulum is formed by attaching a mass m = 500 g to a string of length L = 1.00 m, then allowing the mass to move in a circle of radius of R = 20.0 cm. The string traces out the surface of a cone, hence the name.

a. What is the tension in the string?

b. What is the frequency of motion of the mass, in revolutions per minute (rpm)?