If a gymnast, sitting on a rotating stool with his arms outstretched, suddenly

If a gymnast, sitting on a rotating stool with his arms outstretched, suddenly lower his hands, then

Options

(a) The angular velocity decreases
(b) His moment of inertia decreases
(c) The angular velocity stays constant
(d) The angular momentum increases

Correct Answer:

The angular momentum increases

Explanation:

A gymnast sitting on a rotating stool with his arms outstretched. Suddenly when he lower his hands his moment of inertia I decreases. Since his angular momentum Iω remains constant and I decreases, his angular velocity ω increases.

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View Comments (1)

  • The angular momentum increases because it depends on radius.Here when he lowers his hand the radius increases.

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