Back in school years, in the seventh or eighthclass, each person gets acquainted with the new concept of dynamic physics - friction. However, as they mature, many forget what friction is and how this force acts. Let's try to understand this topic.
Трение - это явление, которое заключает в себе the following meaning: when two bodies come into contact with each other, a special interaction forms at the place of their contact, which prevents the bodies from moving relative to each other. It is clear that it is possible to calculate the value of the interaction of these bodies. The force of friction is just the same and characterizes this interaction quantitatively. If friction occurs between solids (for example, the interaction of a book with a bookshelf or an apple with a table), then this interaction is called dry friction.
It should be understood that friction is a force that haselectromagnetic nature. This means that the cause of this force is the interaction between the particles that make up a particular body.
Due to the diversity of our worldobjects it is possible to determine that each of them has its own structure and has individual properties. This means that the interaction between different objects will be different. For a correct understanding of the essence and proper solution of many problems in physics, it is customary to conventionally divide three types of friction. So, we will analyze each separately:
Трение - это незаменимое явление, без которого мы would not be able to do basic things: walk, sit, or just hold objects in their hands. Therefore, do not underestimate the value of friction. As the French physicist Guillaume said: "If there were no friction, our Earth would be without a single roughness, it would be like a liquid drop."
Perhaps the best example that most accuratelycharacterizes friction, is the work of the wheel. Even in antiquity, it was observed that the rolling friction force is much less than the sliding friction forces. It is the indisputable advantage of rolling friction that caused people to put logs or rollers to move heavy and bulky goods. Over time, people improved their knowledge of the amazing properties of rolling friction, watched the movement of objects under the influence of friction, and finally invented the wheel! In the modern world, it is impossible to imagine life without these irreplaceable parts, because the wheels are the second “engines” of any transport!
Как и любая другая сила, сила трения обладает integer values. In order to accurately determine how much force will be required to move or other types of work, it is necessary to calculate the force of static friction. This is usually done by engineers when, for example, they build factories or invent new devices. However, even ordinary schoolchildren face certain tasks where it is necessary to calculate the friction force. So, to calculate its value, you just need to use a simple formula: Ffriction = K * N, where k is the coefficient of friction.The value of all coefficients always depends on the surface of the object on which the body moves or interacts with. "N" in our formula means the reaction force of reliance on the body. It depends primarily on body weight, which is in contact with the surface of the support.
Suppose a body of mass m = 3 kg is located onhorizontal board. The coefficient of friction between the wooden board and the body is 0.3. How to find the value of friction force? Very simple, just need to substitute our values in the formula. Only it is necessary to take into account that N in this case is equal to body weight (according to Newton's 3rd law). So, the required force is equal to (m * g) * k = (3 kg * 10 m / s2) * 0.3 = 9 H.
