Serway & Jewett — Motion in Two Dimensions: Problem 20

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 \( 8.00 \text{ rev/s} \) when the length of the chain is \( 0.600 \text{ m} \). When he increases the length to \( 0.900 \text{ m} \), he is able to rotate the ball only \( 6.00 \text{ rev/s} \). (a) Which rate of rotation gives the greater speed for the ball? (b) What is the centripetal acceleration of the ball at \( 8.00 \text{ rev/s} \)? (c) What is the centripetal acceleration at \( 6.00 \text{ rev/s} \)?