To understand the notion of friction force, it is convenient to analyze each of the terms that make up the expression.

In the field of physical, is called force (word from the Latin fortia) to the cause that can alter the shape or state of movement or rest of a body. The concept is also used to refer to the ability to exert resistance or tolerate weight.

Touch, on the other hand, it is the act and consequence of rubbing or rubbing: removing a superficial piece of something, touching something lightly or softly.

All these ideas can help us understand what are friction forces. This is how they are called those forces that are generated between bodies that are in contact. These forces produce a endurance to the movements of one object with respect to the other.

The surface of a Body is never completely smooth: in all cases, it presents certain roughness. Therefore, if one body is in contact with another, the rough edges of both fit together, generating resistance to eventual movement.

This means that, if we want to drag an object that is on the ground, we will have to make an effort to achieve that said object leave your resting state, as there will be a static friction force who will oppose displacement.

The effective force that will allow to move the objective, in short, it will be equal to the sum of the applied force and the friction force (equivalent to that necessary to overcome the resistance that, in the opposite direction, exerts the static friction force).

In addition to all the above, we cannot ignore the existence of another series of interesting data on friction force. Among these we can highlight the fact that throughout history this has been very important for society to advance in certain areas. Thus, for example, it must be emphasized that it was precisely the friction force between wood that led man to discover how to make fire.

In the same way, it is interesting to know that Leonardo da Vinci was the pioneer in speaking and studying the force of friction. However, it would be necessary to wait until the seventeenth century for the French physicist Guillaume Amontons to take up his ideas and develop an exhaustive work that resulted in the laws of the aforementioned force. Specifically, these laws came to establish three maxims that are still key today:
-That force does not depend on what the apparent contact area is.
-The force of friction comes to oppose what is the displacement of a block on a plane.
-The force of friction is proportional to what is the normal force that the block performs on the aforementioned plane.

Laws that would later be joined by another that was established by another Gallic scientist named Coulomb. Specifically, we are referring to the fact that when the movement of the block on the plane has already begun, the friction force is totally independent of the speed.