Aplayground merry-go-round with a radius of 1.80 m has a mass of 120 kg and is rotating with an angular speed of 0.400 rev/s. what is its angular speed after a 37.5-kg child gets onto it by grabbing its outer edge? the child is initially at rest.

0.304 rev/s

Explanation:

Given

radius

mass of Merry go round  

mass of child

Initial moment of Inertia of system

assuming all the mass is at periphery

Final Moment of Inertia

Conserving angular momentum

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