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 physics , force is called force (a 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 a weight.
Rubbing , on the other hand, is the act and consequence of rubbing or rubbing: removing a superficial piece of something, touching something lightly or gently.
All these ideas can help us understand what friction forces are. This is what those forces that are generated between bodies that are in contact are called. These forces produce resistance to the movements of one object with respect to the other.
The surface of a body is never completely smooth: in all cases, it has certain roughness . Therefore, if one body is in contact with another, the asperities 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 make said object leave its state of rest, since there will be a static friction force that will oppose the movement.
The effective force that will allow the target to move will ultimately 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 everything indicated, 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 precisely the force of friction between wood was what 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 talking about and studying the force of friction. However, we would have to wait until the 17th century for the French physicist Guillaume Amontons to take up his ideas and develop exhaustive work that resulted in the laws of the aforementioned force. Specifically, these laws established three maxims that remain 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 becomes proportional to the normal force that the block exerts on the aforementioned plane.
These laws would later be added to another that was established by another French 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.