A person is standing on a rotating table with metal spheres in his outstretched hands.If he draws his hands inwards towards his chest,what will be the effect on his angular speed?

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Solution

The angular momentum is proportional to the angular speed and moment of inertia i.e., $L = I ω$
so when you folds your hand inwards and bring close to the chest, distance from the axis(body) decreases. the moment of inertia decreases. so therefore the angular speed increases with respect to initial values to conserve the angular momentum.

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