posted by Help!:) .
In a playground there is a small merry-go-round of radius 1.40 m and mass 140 kg. The radius of gyration is 0.960 m. A child of mass 43.0 kg runs at a speed of 3.70 m/s tangent to the rim of the merry-go-round while it is at rest, and then jumps on. Find the angular velocity (in radians/second) of the merry-go-round and child together. Neglect friction.
You must be having an identity crisis. You've posted physics questions under four different names in the last few minutes.