A group of students observes that a wooden block (m = 0.40 kg) on the end of a string with a radius of 0.7 meters makes 12 rotations in 20.7 seconds when twirled.

Question

Calculate the centripetal acceleration of the wooden block:

Calculate the tension in the string acting on the wooden block:

Answer 1

a=v^2/r=(2PIr/perioid)^2/r
= 4PI^2 r/(12/20.7)

tension= mass*acceleration

Answer 2

11.9