Newton's Third Law of Motion is commonly known to people as: for every action there is an equal but opposite reaction. The real law states: Whenever there are two objects and one object exerts a force on the other object, the second object exerts an equal and opposite force on the first object. There are names for the two forces within an interaction. One force is called the action force and the other force is called the reaction force. Because the forces are simultaneous, it does not matter which force is called the action or reaction force. The law occurs every day and to every one but not all people know that when they walk they exert a force on the ground and the ground exerts a force on them to propel them forward. Other examples of the third law of motion in action are a person pushing on a wall, a gun being fired, a book resting on a desk, and a car crash. As you can see from the examples, for an interaction there must be at least two objects.

In the example of a gun being fired, the bullet pushes back on the gun and the gun pushes forward on the bullet. The forces are equal but why does is the acceleration of the bullet so much greater and so much more noticeable than the acceleration of the gun? The bullet accelerates faster because it has a smaller mass than the gun. Also, if one of the objects has an extremely larger mass compared to the other object, the acceleration of the larger object is either barely or not visible to the human eye. An example would be if a person jumped and then landed on the ground. A person watching could see the person go up but they would not see the earth go downward.