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FMA-2024-25 · 2024 F = ma (AAPT)

2024 F = ma Exam — Question 25

A yo-yo consists of two massive uniform disks of radius R connected by a thin axle. A thick string is wrapped many times around the axle, so that the end of the string is initially a distance R from the axle. Then, the end of the string is held in place and the yo-yo is dropped from rest. Assume that energy losses are negligible, and that the string has negligible mass and always remains vertical. Below, we show a cross-section of the yo-yo partway through its descent. Between the moment the yo-yo is released and the moment the string completely unwinds, which of the following is true regarding the yo-yo’s acceleration?
Source: Question 25, 2024 F = ma Exam, © 2024 American Association of Physics Teachers (AAPT) and the U.S. Physics Team. Adapted by PhysicsTrainer: reformatted into a separate question and answer choices for online multiple-choice practice; any shared setup from nearby questions is repeated here. Not affiliated with or endorsed by AAPT or the U.S. Physics Team.