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Byju's Answer

Standard XII

Physics

Race of Rollers

A girl sits n...

Question

A girl sits near the edge of a rotating circular platform. If the girl moves from circumference towards the center of the platform then the angular velocity of the platform will :

decrease.

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increase.

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remain same.

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becomes zero.

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Solution

The correct option is B increase.
The moment of inertia of the circular platform is maximum when the girl is at the circumference. When she moves towards the center the moment of inertia decreases thereby increasing the angular velocity of the circular platform using the principle of conservation of angular momentum. $I_{1} ω_{1} = I_{2} ω_{2}$

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