Free AP Physics C lesson

Kepler's Laws

This AP Physics C: Mechanics lesson is designed for AP Physics C self-study. It includes 1 video lesson, 2 practice questions, and an estimated completion time of 12 minutes.

Video lessons

  1. Kepler's Laws of Planetary Motion

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Practice covered

  1. According to Kepler's Second Law, a planet sweeps out equal areas in equal times. What does this imply about the planet's speed at different points in its orbit?
  2. According to Kepler's Third Law, the ratio T^2 / R^3 is constant for all planets orbiting the same star, where T is the orbital period and R is the semi-major axis. This constant equals 4pi^2 / GM_s. If a planet has an orbital period of 8 years and orbits at 4 AU from its star, what would be the orbital period (in years) of another planet orbiting the same star at a distance of 9 AU?
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