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F = ma (11–17)
Fluids
FMA-2025-16 · 2025 F = ma (AAPT)

2025 F = ma Exam — Question 16

Two soap bubbles of radii R1 = 1 cm and R2 = 2 cm conjoin together in the air, such that a narrow bridge forms between them. Assuming the system starts in equilibrium, the bubbles are extremely thin, and that air can flow freely between the bubbles through the bridge, describe the evolution and final state of the bubbles.
Source: Question 16, 2025 F = ma Exam, © 2025 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.