A rock in a sling is swung around in a circle. How would the centripetal force change if the rock was 9 times lighter?

1 Answer
Nov 4, 2015

The force would be #1/9th# of that required to spin the larger rock at the same speed.

Explanation:

The force required for angular acceleration is proportional to the mass and the rate of acceleration.
#F = ma#
In this case we usually know either an angular speed (#omega#) or an instantaneous velocity (#v#) and a radius (#r#). So it's also correct to write either of these forms:
#F=mv^2/r#
#F=mromega^2#

In either case the force required changes in direct proportion to the mass. If #m=9# the force would be nine times larger than the case where #m=1#.