Test Prep for AP® Courses

6.5 Newton’s Universal Law of Gravitation


Jupiter has a mass approximately 300 times greater than Earth’s and a radius about 11 times greater. How will the gravitational acceleration at the surface of Jupiter compare to that at the surface of the Earth?

  1. Greater
  2. Less
  3. About the same
  4. Not enough information


Given Newton’s universal law of gravitation (Equation 6.40), under what circumstances is the force due to gravity maximized?3

In the formula g=GMr2g=GMr2, what does G represent?

  1. The acceleration due to gravity
  2. A gravitational constant that is the same everywhere in the universe
  3. A gravitational constant that is inversely proportional to the radius
  4. The factor by which you multiply the inertial mass to obtain the gravitational mass


Saturn’s moon Titan has a radius of 2.58 × 106 m and a measured gravitational field of 1.35 m/s2. What is its mass?5

A recently discovered planet has a mass twice as great as Earth’s and a radius twice as large as Earth’s. What will be the approximate size of its gravitational field?

  1. 19 m/s2
  2. 4.9 m/s2
  3. 2.5 m/s2
  4. 9.8 m/s2


4. Earth is 1.5 × 1011 m from the Sun. Mercury is 5.7 × 1010 m from the Sun. How does the gravitational field of the Sun on Mercury (gSM) compare to the gravitational field of the Sun on Earth (gSE)?