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} Nm^{2}/kg^{2}

M_{1} is the mass of the first body in kg

M_{2} is the mass of the second body in kg

R is the distance from the center of M_{1} to the center of M_{2}
This is the first of several important inversesquare relationships that we will study: light intensity and electrostatic force are two others.
Let's practice this relationship by looking at a few examples.
