An athlete swings a ball, connected to the end of a chain, in a horizontal circle. The athlete is able to rotate the ball at the rate of 8.16 rev/s when the length of the chain is 0.600 m. When he increases the length to 0.900 m, he is able to rotate the ball only 6.35 rev/s.
(a) Which rate of rotation gives the greater speed for the ball?
(b) What is the centripetal acceleration of the ball at 8.16 rev/s?
(c) What is the centripetal acceleration at 6.35 rev/s?