What is friction? What is the significance of this physical quantity? In the surrounding world there are many interesting physical phenomena: lightning, snow, hail, thunder. What is friction? We analyze the features of this process, its scope.
Examples of occurrence
If you scatter, you can ride on an ice path to a certain length. On asphalt, a similar situation is impossible. What is the reason for this difference? Determines this difference friction. Physics examines in detail all the causes of this force.
Characteristic
The force of friction of motion arises when two bodies come into contact. One of them will impede the movement of the second, this force is the force of friction. There are several options for such forces arising under certain conditions.
Varieties of friction
If you need to move a heavy cabinet, it is quite problematic for one person to do this. It is necessary to increase the "shear" force. In this case, the rest friction force will increase. Its direction is opposite to the movement of the movable cabinet.
At that moment, when the traction force becomes larger than the static friction, the cabinet changes its location. At this moment, another friction force appears. The acceleration possessed by the friction of motion determines the nature of the movement. If it prevails over traction, then it will be difficult to talk about fast movement.
Sometimes on roads there are situations in which several people try to move a stalled vehicle. When pushing a car, they use rolling friction. During the rolling of the body along the surface of the road, acceleration occurs.
The friction coefficient in this case depends on the pattern on the tires, the condition of the roadway, weather conditions.
If a round ball moves along the surface, the friction is insignificant. This phenomenon is widely used in everyday life. Massive furniture is equipped with special wheels, allowing (if necessary) to move it from one section of the room to another.
Strength Features
What is friction? This is a force directed opposite to the movement of the body. This physical quantity helps to reduce the speed of the body. If there wasn’t this force, it would be possible to move on rollers or a bicycle without making any effort for this. It is the existence of the friction force that explains the movement of the vehicle a certain distance after the engine has been turned off. The main types of friction are: rolling, sliding, rest.
Nature of friction
Arguing over what friction is, it is necessary to identify the nature of the occurrence of this force. If you have a smooth surface, such as ice or a polished table, you can see minor roughness only with a magnifying glass or a microscope. It is for them that the body moving along the surface will “cling”. Since the moving object itself has certain irregularities, there is contact between the surfaces.
At first, the bodies are attracted to each other, but as the moving object moves away, the adhesion is destroyed. As a result, an oscillation of atoms freed from mutual attraction occurs. Similarly, the state of the tensile spring can be described.
During friction, an increase in temperature is observed, that is, a certain amount of heat is released.
The causes of friction
This force arises in the presence of irregularities on the surface of the contact of two bodies, as well as due to the strength of the intermolecular interaction.
The friction force depends on the material from which the contacting surfaces are made, the weight of the interacting objects. For the mathematical calculation of this physical quantity, there is a special formula that relates the friction force to the force acting on the support, as well as to the coefficient of friction.
It reflects the dependence of the required strength on the selected material, as well as on the quality of its processing. The unit reaction of the support when moving the body along a horizontal surface is equal to its weight. In the case of an inclined plane, its value decreases, therefore, from a steep mountain skiing (sledding), you can ride a very impressive distance.
This power does a certain job. If the body will move, a prerequisite is the completion of work. The force of friction tries to prevent the movement of the object on the surface. That is why the work done by her has a negative meaning.
Application of friction
The man in his daily life is always accompanied by the force of friction. She is able to have both positive and negative effects. For example, if there wasn’t such a force in nature, the bodies would slide down, the transport would fall apart into separate parts.
It would be difficult to tie shoelaces on shoes, to keep interior items in a constant place. A man in the absence of friction could not have taken even one step. In order to solve a similar problem, during heavy ice, they try to sprinkle the tracks with a thick layer of sand. By increasing the surface roughness, the friction force is also increased, helping people to easily move along slippery sections of the road or sidewalk.
But in addition to the positive effect, friction often exhibits negative properties. People know how to increase and decrease its value, getting the maximum benefit for themselves. For example, in order to transfer a heavy load from one place to another, use wheels. In order to turn sliding into rolling, for example, surface roughness is increased.
Depending on what pattern was applied to the tires, they are used to move the vehicle along different sections of the road.
Rubber has a black color, since coal is part of it. It is necessary to give tires the strength, necessary stiffness, increase friction on the road surface. With the correct calculation of the friction force, you can get the desired result.