Newtons Third Law of Motion

Katrine A.2012

Every action has a reaction; throughout this writing piece I will explain Newton’s third law of motion. During this if you do not already know what Newtons third law of motion is then you will hopefully know it by the end, and then you can talk to all your friends about it. The paper will include a few diagrams explaining how it works through the visual eye and a lot of explanations of what it is and how it relates to our everyday life.

Newtons Third Law
Every action has an equal and opposite reaction. This law of motion as well as the others can be found and is used in everyday life. For example, when we walk we apply a force on the ground, the ground applies an equal and opposite force enabling us to move. Also, when we put a book down on a table or surface the reason that it stays in the same place and doesn’t move is because the book applies a force on the table and the table applies an equal and opposite force. The third law of motion will always consist of two things; it can be either objects or people. This law builds on the other two laws of motion from newtons three laws of motion. It predicts what will happen when two forces come into contact. It is very easy to illustrate the third law of motion in everyday life. The difference of the mass or weight in objects or people can cause different outcomes of the third law.

You may not always be able to see the reaction of the third law of motion. This law is very important and without this law taken into account it can upset many calculations. This law states that every action we make or every action something makes that every action should have a reaction to that action and it should always be in the opposite direction. It will always be found outside the science world. When you are talk about two people for the third law of motion it’s because when they are together or standing close then there is an action that is acting on their bodies and a reaction that is keeping them in the same place. There is no such thing as an unprepared force.
A large variety of action and reaction pairs are shown in nature. In every interaction between people and things there is an action and a reaction, or a reaction and action pair.

Action and reaction is the subject of Newtons Third Law of Motion. This law does not always seem reasonable and does not always make sense because if you are pushing on a box it does not seem to be pushing on you. But in Newtons Second Law, it does state that force and acceleration are related, but they aren’t always identical.If, however, the shoebox is sitting next to a wall and you push it toward the wall, the shoebox will push on the wall and the wall will push back. The shoebox will then stop moving. You can push it harder, but the box will break before it goes through the wall because it isn't strong enough to handle the stronger force of the wall. The forces are always equal no matter what, and it may seem like there is no reaction, but there actually is. Newtons secon and first law both help explain the third law.

We experience this law without evening thinking about it; almost everything that we do has an action and a reaction. A basic way to think about the third law of motion is that if you push on it pushes back. Like when you are pushing your friend or your enemies with your hands then you are applying newtons third law in motion. The action and the reaction pair act along the same lines. This law underlines the basic manner in which a force comes into existence. Force results from the interaction of two bodies, always appearing in pair. There is no such thing as a lonely or a single force because every force must have a partner which makes it a pair.

Force Pairs
Force pairs are a very big part of the Third law of motion because between each two objects in the third law of motion there is a force. A force pair is art of the third law, but it is basically a force between a pair of objects. A pair as in meaning two objects. Since the third law of motion says that there has to be two objects or people than the force that is in between them is a force pair, In all a force pair is related to the third law of motion because between each force pair there is an equal and opposite reaction. There is no such thing as an unprepared force.

Brief History of the Third Law of Motion
It was formulated by Isaac Newton in the 16th and 17th century. It is a different type of law than most people normally think of when we say a law. This is because it is a law of motion it is simply there for people to follow if they are doing something like that and to know what makes things move and stop. Isaac Newton first showed his third law of motion in the Principia Mathematical Philosophiae Naturalis in the year 1686.

Diagram to Explain
1) In these two diagrams explain the third law of motion and how it works. In the first diagram you can see how when a runner exerts or applies a force on the ground by her foot when running or walking the reason that she is able to move is because the ground she is running and walking on reacts with the same amount of force, but just in the opposite direction so she doesn’t sink into the ground or worse. All of this enables the runner to move forward. It happens every time you take a step or apply a force to the ground on surface.
Diagram of runner.jpg
Figure 1. Diagram of Runner.

2) When a bird flies then it uses its wings to move forward and to fly. When the bird is in the air and is propelling itself forward then it has to push against something because that is how we all move. The way the bird moves is that it flaps its wind every few seconds and when it does that it pushes all the air in the sky downwards and backwards which makes the bird move forward. To keep the bird afloat in air so it does not rise into air. The air then pushes back with the same amount of force which keeps the bird in the same place. So in all, the bird moves by using its wings and the air that they out each time they flap pushes the air behind which makes the bird go forward and then it also goes downward, but the air pushes back with the same amount of force which enables the bird to keep in the same height while it is flying and moving.
Figure 2. Diagram of Bird Flying.

A Little about Newton

Isaac Newton was born on December 25, 1642, in Woolsthrope, England. His father had sadly died before he was born, so Newton had never physically seen his father before. Later on Newton attended Trinity College, Cambridge, in 1661; he began studying the ancient teachings of Aristotle, because that was customary then. He graduated from Trinity College in 1665 and went back to Woolsthrope and there he continued on with the studies of light, gravity, and mathematics. He was the “inventor” of the three laws of motion. They are known as the three laws in motion, also known as the first law in motion, the second law in motion, and the third law in motion. He first these laws in the year of 1686 which was a while after graduated from college. He also described the universal gravitation. He was an unorthodox Christian, even though that was his religion he wrote many biblical hermeneutics, he wrote more hermeneutics than he did on physics and science. He died on the 20 March in 1727 and lived to the remarkable, in that time, age of 80. The place of his death was in England.
Figure 3. Isaac Newton.

Exert: To put forth or into use.
Force: power or strength of human being or objects
Mass: the shape of something as well as the size
Motion: action or process of moving or changing
Physics: science that deal with matter, energy, force and motion


Dumas, Leila. Forces, Motion, and Energy. New York: Holt, 2007. Print.

Gregersen, Erik. Heat, Force, and Motion. New York: Britannica, 2011. Print.

Henderson, Tom. Newtons Third Law of Motion. The Physics Classroom. ComPADRE: 2012. Web. 9/24/2012

"Newton, Isaac." Britannica Elementary Encyclopedia. Encyclopædia Britannica Online School Edition.EncyclopædiaBritannica, Inc., 2012. Web. 13Sept. 2012.