Example : o
o
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When a person is rotating with hands stretched , so the moment of inertia will be more because distribution of mass is far from the axis of rotation .
As the person brings his arms close to body , moment of inertia decreases because the mass is now distributed close to axis .
In this situation no external torque is applied , means angular momentum is conserved .
o Iω = constant . o
As I decrease , angular velocity ω