Physics: basic concepts, formulas, laws. The basic laws of physics that a person must know

To be interested in the surrounding world and the laws of its functioning and development is natural and correct. That is why it is reasonable to pay attention to natural sciences, for example, physics, which explains the very essence of the formation and development of the universe. Basic physical laws are easy to understand. Already at a very young age the school introduces children to these principles.

For many, this science begins with the textbook "Physics (Grade 7)." The basic concepts and laws of mechanics and thermodynamics open before students, they get acquainted with the core of the main physical laws. But should knowledge be limited to a school bench? What physical laws should everyone know? This will be discussed later in the article.

Science of Physics

Many of the nuances of the science described are familiar to everyone from early childhood. And this is due to the fact that, in essence, physics is one of the areas of natural science. It narrates about the laws of nature, the effect of which affects the life of everyone, and in many ways even provides it, about the features of matter, its structure and laws of motion.

The term "physics" was first recorded by Aristotle in the fourth century BC. Initially, it was synonymous with the concept of "philosophy". After all, both sciences had a single goal - to correctly explain all the mechanisms of the functioning of the universe. But already in the sixteenth century, as a result of the scientific revolution, physics became independent.

General law

Some basic laws of physics are used in various branches of science. In addition to these, there are those that are generally considered to be common to the whole of nature. It is about the law of conservation and transformation of energy.

It implies that the energy of each closed system is invariably preserved when any phenomena occur in it. Nevertheless, it is capable of transforming into another form and effectively changing its quantitative content in various parts of the said system. At the same time, in an unclosed system, the energy decreases, provided that the energy of any bodies and fields that interact with it increases.

In addition to the above general principle, physics contains the basic concepts, formulas, laws that are necessary for the interpretation of processes occurring in the surrounding world. Their research can be an incredibly fun activity. Therefore, in this article the basic laws of physics will be briefly considered, and in order to understand them deeper, it is important to give them full attention.

Mechanics

Many young scientists discover the basic laws of physics of the 7th-9th grades of the school, where the branch of science is more fully studied, such as mechanics. Its basic principles are described below.

1. The law of relativity of Galileo (also called the mechanical law of relativity, or the basis of classical mechanics). The essence of the principle is that under similar conditions, the mechanical processes in any inertial frame of reference are completely identical.
2. Hooke's Law. Its essence is that the greater the impact on the elastic body (the spring, the rod, the console, the beam) from the side, the greater its deformation.

Newton's laws (they are the basis of classical mechanics):

1. The principle of inertia says that any body can be at rest or move evenly and rectilinearly only if no other bodies act on it in any way, or if they somehow compensate each other's action. To change the speed of movement, it is necessary to act on the body with some force, and, of course, the result of the action of the same force on different bodies will also differ.
2. The main regularity of dynamics asserts that the greater the resultant forces that currently act on a given body, the greater is the acceleration obtained by it. And, accordingly, the more body weight, the less this indicator.
3. Newton's third law says that any two bodies always interact with each other in an identical pattern: their forces are of the same nature, are equivalent in magnitude and necessarily have the opposite direction along the straight line that connects these bodies.
4. The principle of relativity asserts that all phenomena occurring under the same conditions in inertial frames of reference pass in an absolutely identical manner.

Thermodynamics

A school textbook that reveals basic laws to students ("Physics, Grade 7"), acquaints them with the basics of thermodynamics. We briefly discuss its principles further.

The laws of thermodynamics, which are basic in this branch of science, are of a general nature and are not connected with the details of the structure of a particular substance at the atomic level. By the way, these principles are important not only for physics, but also for chemistry, biology, aerospace engineering, and so on.

For example, in the named branch there exists a rule which does not give a logical definition, that in a closed system, the external conditions for which are unchanged, an equilibrium state is established with time. And the processes that continue in it invariably compensate each other.

Another rule of thermodynamics confirms the desire of the system, which consists of a colossal number of particles characterized by chaotic motion, to an independent transition from the more probable states to the more probable ones.

And the law of Gay-Lussac (also called the gas law) states that for a gas of a certain mass under conditions of stable pressure, the result of dividing its volume by absolute temperature necessarily becomes a constant value.

Another important rule of this branch is the first law of thermodynamics, which is also commonly called the principle of conservation and transformation of energy for a thermodynamic system. According to him, any amount of heat that was communicated to the system will be spent exclusively on the metamorphosis of its internal energy and the performance of its work in relation to any acting external forces. It is this regularity that has become the basis for the formation of the scheme of operation of thermal machines.

Another gas law is the law of Charles. It says that the greater the pressure of a certain mass of an ideal gas under conditions of maintaining a constant volume, the greater its temperature.

Electricity

Opens young scientists with interesting basic laws of physics of the 10th grade of the school. At this time, the main principles of nature and the laws of the action of electric current, as well as other nuances, are studied.

Ampere's law, for example, asserts that conductors connected in parallel, through which the current flows in the same direction, are inevitably attracted, and in the case of the opposite direction of current, respectively, repel. Sometimes the same name is used for physical law, which determines the force acting in the existing magnetic field on a small portion of the conductor currently conducting a current. It is called - the power of Ampere. This discovery was made by scientists in the first half of the nineteenth century (namely in 1820).

The law of conservation of charge is one of the basic principles of nature. It says that the algebraic sum of all electric charges arising in any electrically isolated system is always preserved (becomes constant). Despite this, the above principle does not exclude the appearance of new charged particles in such systems as a result of certain processes. Nevertheless, the total electric charge of all newly formed particles must necessarily be zero.

The Coulomb law is one of the basic in electrostatics. He expresses the principle of the force of interaction between fixed point charges and explains the quantitative calculation of the distance between them. The Coulomb law allows us to substantiate the basic principles of electrodynamics in an experimental way. It says that fixed point charges invariably interact with each other with a force that is higher, the larger the product of their quantities and, consequently, the smaller the smaller the square of the distance between the charges under consideration and the dielectric constant of the medium in which the described interaction takes place.

Ohm's law is one of the basic principles of electricity. It states that the greater the strength of a constant electric current acting on a certain section of the circuit, the greater the voltage at its ends.

"The rule of the right hand" is a principle that allows you to determine the direction in the conductor of a current moving under the conditions of the magnetic field in a certain way. To do this, it is necessary to place the right hand brush so that the lines of magnetic induction touch the open palm of your hand and draw the thumb in the direction of the conductor's movement. In this case, the remaining four straightened fingers will determine the direction of movement of the induction current.

Also, this principle helps to determine the exact location of the lines of magnetic induction of a rectilinear conductor that conducts current at a given moment. This is the case: place the thumb of the right hand in such a way that it indicates the direction of the current, and with the other four fingers grasp the conductor. The location of these fingers and will demonstrate the exact direction of the lines of magnetic induction.

The principle of electromagnetic induction is a regularity that explains the operation of transformers, generators, electric motors. This law consists in the following: in a closed loop, the generated electromotive force of induction is the greater, the greater the rate of change of the magnetic flux.

Optics

The branch "Optics" also reflects part of the school curriculum (the basic laws of physics: grades 7-9). Therefore, these principles are not so difficult to understand as it may seem at first glance. Their study brings with them not just additional knowledge, but a better understanding of the surrounding reality. The basic laws of physics, which can be attributed to the field of optics, are as follows:

1. The Guinness principle. It is a method that allows you to effectively determine in each specific fraction of a second the exact position of the wave front. Its essence consists in the following: all the points that are on the way at the front of the wave in a certain fraction of a second, in essence, in themselves become sources of spherical waves (secondary), while placing the wave front in the same fraction of a second is identical to the surface , Which envelopes all spherical waves (secondary). This principle is used to explain the existing laws related to the refraction of light and its reflection.
2. The Huygens-Fresnel principle reflects an effective method of resolving issues related to the propagation of waves. He helps to explain the elementary problems associated with diffraction of light.
3. Law of reflection of waves. It is applied equally for reflection in the mirror. Its essence lies in the fact that both the descending ray, and the one that was reflected, as well as the perpendicular constructed from the point of incidence of the ray, are located in a single plane. It is also important to remember that the angle at which the beam falls is always absolutely equal to the angle of refraction.
4. Principle of refraction of light. This change in the trajectory of the motion of an electromagnetic wave (light) at the moment of motion from one homogeneous medium to another, which differs significantly from the first in a number of refractive indices. The speed of light diffusion in them is different.
5. The law of rectilinear light propagation. In its essence, it is a law relating to the field of geometric optics, and consists in the following: in any homogeneous medium (regardless of its nature) light propagates strictly rectilinearly, according to the shortest distance. This law simply and easily explains the formation of the shadow.

Atomic and nuclear physics

The basic laws of quantum physics, as well as the fundamentals of atomic and nuclear physics, are studied in the upper grades of the secondary school and higher educational institutions.

So, Bohr's postulates are a series of basic hypotheses, which became the basis of the theory. Its essence is that any atomic system can remain stable only in stationary states. Any radiation or absorption of energy by an atom necessarily occurs using the principle, the essence of which is the following: the radiation associated with transport becomes monochromatic.

These postulates refer to the standard school curriculum, which studies the basic laws of physics (11th grade). Their knowledge is compulsory for the graduate.

The basic laws of physics that a person must know

Some physical principles, although they relate to one of the branches of this science, are nevertheless of a general nature and should be known to everyone. Let's enumerate the basic laws of physics that a person should know:

• The law of Archimedes (refers to the areas of hydro- and aerostatics). It implies that a kind of buoyancy force acts on any body that has been immersed in a gaseous substance or liquid, which is necessarily directed vertically upwards. This force is always numerically equal to the weight of the liquid or gas displaced by the body.
• Another formulation of this law is the following: a body immersed in a gas or liquid necessarily loses as much weight as it constituted the mass of the liquid or gas into which it was immersed. This law became the basic postulate of the theory of swimming of bodies.
• The law of universal gravitation (discovered by Newton). Its essence lies in the fact that absolutely all bodies are inevitably attracted to each other with a force that is greater, the larger the product of the masses of these bodies and, correspondingly, the smaller the smaller the square of the distance between them.

This is the 3 basic laws of physics that everyone should know, who wants to understand the mechanism of functioning of the surrounding world and the peculiarities of the processes occurring in it. To understand the principle of their action is quite simple.

The value of such knowledge

The basic laws of physics must be in the luggage of man's knowledge, regardless of his age and type of activity. They reflect the mechanism of existence of all today's reality, and, in essence, are the only constant in a continuously changing world.

Basic laws, concepts of physics open new possibilities for studying the surrounding world. Their knowledge helps to understand the mechanism of existence of the universe and the motion of all cosmic bodies. It turns us not just into the spies of daily events and processes, but allows us to realize them. When a person clearly understands the basic laws of physics, that is, all the processes around him, he gets the opportunity to manage them in the most effective way, making discoveries and thereby making his life more comfortable.

Results

Some are forced to study in depth the basic laws of physics for the Unified State Examination, others - according to the nature of the activity, and some - from scientific curiosity. Regardless of the goals of studying this science, the benefits of the knowledge gained can not be overestimated. There is nothing more satisfying than understanding the basic mechanisms and patterns of existence of the world around us.

Do not remain indifferent - develop!