4-62. An astronaut in training is spinning around in a device that rotates at 30 revolutions per minute. (a) If the astronaut is 7.5 m from the centre of the device, what is the magnitude of the centripetal acceleration? (b) Express the answer in terms of "g," the magnitude of the acceleration due to gravity. [Ans. (a) 74 m/s2 (b) 7.6 g]



The expression for centripetal acceleration is: 
(A)  ac = v2/r

(B)  ac = 4p2r/T2