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Conservation of angular momentum

AP.PHYS: CON‑5.E (EU), CON‑5.E.1 (EK), CON‑5.E.1.1 (LO), CON‑5.E.1.2 (LO), CON‑5.E.2 (EK), CON‑5.E.2.1 (LO)


A man holding onto two weights with his arms outstretched stands on a platform that is freely rotating about a frictionless axle. When he moves his arms close to his body, his angular velocity increases.
A diagram shows a person standing on a platform with two weights in each hand. Initially, the person’s arms are extended out horizontally. Arrows show that the person brings the weights down until their arms are at rest along their sides.
Which of the following best describes why the man’s angular velocity increased?
Choose 1 answer: