Question

A 900-kg merry-go-round (a flat, solid cylinder) supports 10 children, each with a mass of 50.0 kg, located at the axis of rotation (thus you may assume the children have no angular momentum at that location). You need to describe a plan to move the children such that the angular velocity of the merry-goround decreases to one-half its initial value. ou decided to redistribute the children around the merry-go-round so that each one is the same distance, R(Child), from the rotation axis.

Find R(Child) in terms of R(Merry-Go-Round).

Answer 1

well, one wants to change the moment of inertia to half. Flat cylinder? should be more like a disk, to me.

Initial I=1/2 900* r^2
final I= 2x of that initial

final I= 1/2 900*r^2+500c^2 where c is the radius of the child from center.
900*r^2=1/2 900*r^2+500c^2
450 r^2=500c^2

solve for c,