Angular momentum/kinetic energy

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When an ice skater pulls weights closer to his body while rotating, his angular velocity increases due to the conservation of angular momentum. This increase in angular velocity also results in a rise in rotational kinetic energy. The additional energy required for this increase comes from the work done by the skater's muscles as they pull the weights inward. Thus, the skater's effort directly contributes to the increase in energy. The interplay between angular momentum and kinetic energy is crucial in understanding this dynamic.
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Homework Statement


An ice skater holds two weights in his outstretched hands and rotates about his vertical axis. Then he brings the weights closer to his hands.In accordance with the law of conservation of angular momentum,the angular velocity of the ice skater increases.But so does the rotational kinetic energy.Where does this extra energy come from?


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The Attempt at a Solution

 
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The muscles in his hands do work on the weights to bring them closer. this will increase the rotational kinetic energy.
 
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