Chapter 4.6, Problem 1C

Newton’s law of universal gravitation describes the gravitational attraction between any two objects. The formula is

$F=G\frac{m_1{m}_2}{r^2}$

where F is the force of the gravitational attraction, $m_1$ and $m_2$ are the masses of the two objects, and r is the distance between the centers of the two objects. G is a number known as the gravitational constant: we’ll see what that number is in a bit.

Newton’s law of universal gravitation certainly looks like a variation equation, especially when you consider that G is a constant. Describe the relationship between the gravitational force between two objects and the distance separating their centers. Your answer should use either the term “directly” or “inversely,” and should describe in plain English what happens to one of those quantities when the other changes.