This document discusses Newton's law of universal gravitation. It defines the law, which states that a force of attraction exists between any two masses and this force is directly proportional to the product of the masses and inversely proportional to the square of the distance between them. It then provides three practice problems that apply this law to calculate gravitational forces between objects of different masses and distances.

1. Law of Universal Gravitation

2. Newton’s Law of Universal Gravitation Equal, opposite forces pull the objects together Source: Griffith, The Physics of Everyday Phenomena , 4th ed. d