 Resource Lesson The Law of Universal Gravitation
The Law of Universal Gravitation states that every object in the universe attracts every other object in the universe with a force that has a magnitude which is directly proportional to the product of their masses and inversely proportional to the distance between their centers squared. where

• G is the gravitational constant, 6.67 x 10-11 Nm2/kg2
• M1 is the mass of the first body in kg
• M2 is the mass of the second body in kg
• R is the distance from the center of M1 to the center of M2

This is the first of several important inverse-square relationships that we will study: light intensity and electrostatic force are two others.

Let's practice this relationship by looking at a few examples.

Refer to the following information for the next four questions.

Given that the gravitational attraction between two objects of mass M that are located a distance r apart is called F.
 How would the force change between these two objects if the distance between them were to be doubled to 2r?

 How would the force change between these two objects if the distance between them were to be halved to ½r?

 How would the force change between these two objects if one object magically doubled in mass while the other object magically tripled in mass while the distance between them stayed the same, r?

 How would the force change between these two objects if one object magically doubled in mass, while the other object magically tripled in mass, and the distance between them doubled to 2r?