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F = ma (First 10)
Simple Harmonic Motion
FMA-2016-08 · 2016 F = ma (AAPT)

2016 F = ma Exam — Question 8

Kepler’s Laws state that I. the orbits of planets are elliptical with one focus at the sun, II. a line connecting the sun and a planet sweeps out equal areas in equal times, and III. the square the period of a planet’s orbit is proportional to the cube of its semimajor axis. Which of these laws would remain true if the force of gravity were proportional to 1/r3 rather than 1/r2?
Source: Question 8, 2016 F = ma Exam, © 2016 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.