The centripetal force is the net force that tends to the center of the circle whenever there is uniform circular motion. The basic equation is
Part 1: Express the speed in terms of the radius of the circle , and the period of one revolution . Then use the expression of velocity to express the centripetal force in terms of the period.
Part 2: The frequency is defined as the reciprocal of the period . Express the centripetal force in terms of frequency.
The speed in uniform circular motion is the distance divided by the period. Since the distance is the circumference of the circle with radius ,