STANDARD Physics Conservation of Angular Momentum MCQ Question
A person, with outstretched arms, is spinning on a rotating stool. He suddenly brings his arms down to his sides. Which of the following is true about his kinetic energy K and angular momentum L?
Both K and L increase
Both K and L remain unchanged
K remains constant, L increases
K increases but L remains constant
Correct Answer
Detailed Explanation
When the person brings his arms closer to his body, the moment of inertia decreases, causing the rotational speed to increase to conserve angular momentum. As a result, the kinetic energy increases while the angular momentum remains constant.
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