physics
posted by Fred on .
A child is twirling a 0.0100 kg ball on a string in a horizontal circle whose radius is 0.118 m. The ball travels once around the circle in 0.460 s.
(a) Determine the centripetal force acting on the ball.
(b) If the speed is doubled, does the centripetal force double? (yes or no)
If not, by what factor does the centripetal force increase?

speed of ball= 2PI*radius/time
a) force= mass*v^2/r
b) what happens when v doubles? 
when v doubles it does the centripetal force does not increase by 2, but rather by 4.