A ball of mass m on a string of length R, swinging around in circular motion, with instantaneous velocity v and centripetal acceleration a.
What is the centripetal acceleration of the ball if the length of the string is doubled?
The equation for the centripetal acceleration is a = v2/r. That is, acceleration is inversely proportional to the radius of the circle. If the radius is doubled, then the acceleration is halved.
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