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## Homework Statement

A .2kg ball travels in a circle of r=1m, one revolution every second, what is the acceleration.

What would happen to the force and acceleration if you double the speed?

## Homework Equations

f=ma

a= (v^2)/r

## The Attempt at a Solution

2∏1m x ≈ 6.3m

Speed of the ball = 6.3m/s

a = (6.3^2)/1 = 40m/s

Fnet = .2kg 40m/s = 8N

The solutions manual says that the Fnet and and a would QUADRUPLE if the speed is doubled. Why the heck would it quadruple?

I'm having a hard time understanding this chapter. Centripetal force makes no sense. If Newton's 3rd law says that for every force there is an equal but opposite force, then why is there not an equal but opposite force OUTWARD when it comes to centripetal force?