Friction is a process in which bodies interact when they move relative to each other. This may be displacement, movement of the body in a liquid or gaseous medium. There is a scientific name for this phenomenon - frictional interaction. As a rule, the study of the friction process is carried out by physics, the section "Mechanics of frictional interaction", and in some cases - tribology.
The friction force is electronic in nature, but only under one condition - the substance is in a normal state.
As for the types of this phenomenon, in the presence of the process of relative motion of bodies, the force that arises from their interaction can be divided into:
- Sliding friction is the force that occurs when the translational movement of one body relative to another. It acts on a given body in a direction that is opposite to the direction of the slip itself.
- Rolling friction or torque. It occurs when the rolling of one of the two interacting forces is relatively different.
- Rest friction is a force that can occur between two bodies in one way or another in contact, and also prevents the appearance of relative motion. As a rule, it occurs during the slightest movement or contact of bodies. Acts in a direction that is opposite to relative movement.
With regard to physics itself, the force of friction and interaction is divided into:
- Dry, when the interaction of solids occurs, and they are not separated by any additional lubricants. This case is much less common in practice and has a distinctive feature - the presence of a high rate of friction at rest.
- Boundary - this is when there are layers in the area of contact, as well as areas of different nature. This friction force in nature is the most common.
- Mixed - in this process, the contact area contains some areas of both liquid and dry friction. It can occur if the bodies are immersed in a liquid, only in this case the friction force will be characterized by the degree of viscosity of the medium.
- Elastohydrodynamic - occurs when a certain internal friction with a material that performs lubricating functions is crucial. As a rule, it occurs with a strong increase in the relative speed of movement.
It is worth noting that, due to the complexity of the physicochemical processes that are associated with this phenomenon during the period of frictional interaction, the friction processes that are carried out cannot be described using the method of classical mechanics.
Answering the question on what the friction force depends, we can say that it is determined by the pressure force and the coefficient of friction. The last indicator directly depends on many factors: on the degree of purity with which this or that surface is processed, on the kind of substances from which the bodies themselves are made, and if speed takes place, then on this indicator. It is important to know that the friction force practically does not depend on the area with which the bodies come into contact.
In conclusion, we can say that the presence of a certain friction makes it possible to move along the surface. For example, in the process of walking, the floor and sole are engaged, which is precisely due to friction. As a result of such contact, the sole is repelled from the floor and the person moves forward.
In the same exact way, the implementation of the clutch of the vehicle wheels with the road. It is in order to improve and increase such grip that new tires and tires are specially developed, and “wing” can be installed on racing cars , which quite strongly press the car to the track.