Centripetal Force
The force that keeps an object moving in a circle is called centripetal force. It's always directed towards the center of the circle. The formula for centripetal force is:
* F = (mv^2) / r
Where:
* F is the centripetal force
* m is the mass of the object
* v is the velocity of the object
* r is the radius of the circular path
The Impact of Speed
Notice that velocity (v) is squared in the formula. This means that if you double the velocity, you increase the force by a factor of 2 squared, which is 4.
Example
Let's say the ball is moving at 1 m/s and the force is 1 N. If you double the speed to 2 m/s:
* F = (m * 2^2) / r = 4 * (m / r)
The force is now 4 times greater.
In Summary
Doubling the speed of a ball swinging in a circle will quadruple the centripetal force needed to keep it moving in that circular path.