Ice sketar rotates with open arms & her moment of inertia is I, rotational speed W. So, angular momentum is I*W. Energy is (1/2)I*W*W(adsbygoogle = window.adsbygoogle || []).push({});

she folds her arms & her moment of inertia decreases to I/2. From conservation of angular momentum rotational speed became double say W*2.

Energy became (1/2)*I/2*W*W*4 = I*W*W ( Energy is doubled, How?)

Please tell me in this caculation where I am wrong?

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# Conservation of angular momentum with energy

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