Free AP Physics C lesson

Gravitational Force & Energy

This AP Physics C: Mechanics lesson is designed for AP Physics C self-study. It includes 3 video lessons, 5 practice questions, and an estimated completion time of 20 minutes.

Video lessons

  1. The Gravitational Force

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  2. Gravitational Potential Energy

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  3. Gravitational Forces and Energies

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Practice covered

  1. Near the surface of Earth, the gravitational field strength g has a value of approximately 9.8 N/kg. What does this value represent?
  2. The mass of Planet X is one-tenth that of Earth, and its radius is one-half that of Earth. What is the acceleration due to gravity at the surface of Planet X?
  3. A person with mass 75 kg standing on Earth's surface has a gravitational potential energy of approximately -4.7 times 10^9 J. What does the negative sign indicate?
  4. A newly discovered planet has twice the mass of Earth, but the acceleration due to gravity on its surface is exactly the same as on Earth's surface. What is the radius of this planet in terms of Earth's radius R_E?
  5. The formula Delta U = mgDelta h is commonly used to calculate changes in gravitational potential energy near Earth's surface. Under what condition is this formula valid?
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