A child swings a tennis ball attached to a 0.662-m string in a horizontal circle above his head at a rate of 4.50 rev/s.

Question

(a) What is the centripetal acceleration of the tennis ball?

m/s2

Answer 1

omega^2 R

omega = 4.5 revs/s * 2 pi radians/rev
= 9 pi rad/s
omega^2 = 81 pi^2 /s^2
so
a = 81 pi^2 * .662
= 529 m/s^2