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 the 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. 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 are opened before schoolchildren, they get acquainted with the core of the main physical laws. But should knowledge be limited to the school bench? What physical laws should every person know? This will be discussed later in the article.
Science physics
Many of the nuances of the described science 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 tells about the laws of nature, the effect of which affects everyone's life, and in many ways even provides it, about the features of matter, its structure and laws of motion.
The term "physics" was first coined 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 applied in various branches of science. In addition to them, there are those that are considered common to all nature. It is a law of conservation and conversion of energy.
It implies that the energy of each closed system during the flow of any phenomena in it will certainly be preserved. Nevertheless, it is able to transform into another form and effectively change its quantitative content in various parts of the named system. At the same time, in an open system, 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 basic concepts, formulas, laws that are necessary for the interpretation of processes occurring in the surrounding world. Exploring them can be incredibly fun. Therefore, this article will discuss the basic laws of physics briefly, and in order to understand them deeper, it is important to give them full attention.
Mechanics
Many young laws of physics are opened to young scientists by grades 7–9 of the school, where such a branch of science as mechanics is more fully studied. Its basic principles are described below.
- Galileo's Law of Relativity (also called the mechanical law of relativity, or the basis of classical mechanics). The essence of the principle is that under similar conditions, mechanical processes in any inertial reference systems are completely identical.
- Hooke's Law. Its essence is that the greater the impact on the elastic body (spring, rod, cantilever, beam) from the side, the greater is its deformation.
Newton's laws (constitute the basis of classical mechanics):
- The principle of inertia informs that any body can be at rest or move uniformly and rectilinearly only if no other bodies influence it in any way, or if they somehow compensate for each other's actions. To change the speed of movement, it is necessary to act on the body with any force, and, of course, the result of the impact of the same force on bodies of different sizes will also vary.
- The main regularity of dynamics states that the more the resultant of forces that are currently affecting a given body, the greater the acceleration it receives. And, accordingly, the more body weight, the less this indicator.
- Newton’s third law states 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 must have the opposite direction along the straight line that connects these bodies.
- The principle of relativity asserts that all phenomena occurring under the same conditions in inertial reference frames pass in an absolutely identical way.
Thermodynamics
The school textbook, which reveals the basic laws to students (“Physics. Grade 7”), introduces them to the basics of thermodynamics. We will briefly consider its principles below.
The laws of thermodynamics, which are basic in this branch of science, are of a general nature and are not related to 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, etc.
For example, in the named industry there is a rule that cannot be logically defined, that in a closed system, the external conditions for which are unchanged, an equilibrium state is established over time. And the processes going on in it invariably cancel each other out.
Another rule of thermodynamics confirms the desire of the system, which consists of a colossal number of particles characterized by chaotic motion, to independently transition from less probable states to more probable ones.
And the Gay-Lussac law (it is also called the gas law) states that for a gas of a certain mass under stable pressure, the result of dividing its volume by absolute temperature will certainly become a constant value.
Another important rule of this industry is the first law of thermodynamics, which is also called the principle of conservation and conversion of energy for a thermodynamic system. According to him, any amount of heat that was communicated to the system will be expended solely on the metamorphosis of its internal energy and its performance in relation to any acting external forces. It is this regularity that has become the basis for the formation of the operation scheme of thermal machines.
Another gas pattern is Charles's law. It says that the greater the pressure of a certain mass of an ideal gas while maintaining a constant volume, the higher 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 are studied, as well as other nuances.
Ampere’s law, for example, states that conductors connected in parallel, along which current flows in the same direction, are inevitably attracted, and in the case of the opposite direction of the current, they repel each other. Sometimes the same name is used for a physical law that determines the force acting in an existing magnetic field on a small section of the conductor that is currently conducting current. They call it that - the power of Ampere. This discovery was made by a scientist 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 states that the algebraic sum of all the 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 certainly be zero.
Coulomb's law is one of the main 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. Coulomb's law makes it possible to substantiate the basic principles of electrodynamics experimentally. It states that fixed point charges certainly interact with each other with a force that is higher, the greater the product of their values and, accordingly, the smaller the smaller the square of the distance between the charges in question 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 says that the greater the strength of the direct electric current acting on a particular section of the circuit, the greater the voltage at its ends.
“Rule of the right hand” is a principle that allows you to determine the direction in the conductor of a current moving in a certain way under the influence of a magnetic field. To do this, it is necessary to position the hand of the right hand so that the lines of magnetic induction figuratively touch the open palm, and extend the thumb in the direction of movement of the conductor. 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 conducting current at the moment. This happens as follows: place the thumb of the right hand so that it indicates the direction of the current, and grasp the conductor with the other four fingers figuratively. The location of these fingers will demonstrate the exact direction of the lines of magnetic induction.
The principle of electromagnetic induction is a pattern that explains the operation of transformers, generators, electric motors. This law is as follows: in a closed circuit, the generated electromotive force of induction is greater, the greater the rate of change of the magnetic flux.
Optics
The Optics industry also reflects part of the school curriculum (basic laws of physics: grades 7–9). Therefore, these principles are not as difficult to understand as it might seem at first glance. Studying them brings not only additional knowledge, but a better understanding of the surrounding reality. The basic laws of physics, which can be attributed to the field of study of optics, are as follows:
- Guines 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 is as follows: all the points that appear on the path at the wave front in a certain fraction of a second, in essence, themselves become sources of spherical waves (secondary), while the placement of the wave front in the same fraction of a second is identical to the surface which bends around all spherical waves (secondary). This principle is used to explain existing laws related to the refraction of light and its reflection.
- The Huygens-Fresnel principle reflects an effective method of resolving issues related to the propagation of waves. It helps explain the elementary problems associated with light diffraction.
- The law of reflection of waves. It is applied equally to reflection in a mirror. Its essence is that both the falling beam and the one that was reflected, as well as the perpendicular built from the point of incidence of the beam, are located in a single plane. It is also important to remember that in this case the angle at which the beam falls is always absolutely equal to the angle of refraction.
- The principle of refraction of light. This is a change in the trajectory of the electromagnetic wave (light) at the moment of movement from one homogeneous medium to another, which differs significantly from the first in a number of refractive indices. The speed of light propagation in them is different.
- The law of rectilinear propagation of light. In essence, it is a law related to the field of geometric optics, and consists in the following: in any homogeneous medium (regardless of its nature), light propagates strictly rectilinearly, over the shortest distance. This law simply and readily explains the formation of shadows.
Atomic and nuclear physics
The basic laws of quantum physics, as well as the foundations of atomic and nuclear physics, are studied in high school and higher educational institutions.
So, Bohr's postulates represent a series of basic hypotheses that became the basis of the theory. Its essence lies in the fact that any atomic system can remain stable exclusively in stationary states. Any radiation or absorption of energy by an atom certainly occurs using the principle, the essence of which is as follows: radiation associated with transport becomes monochromatic.
These postulates belong to the standard school curriculum that studies the basic laws of physics (11th grade). Their knowledge is mandatory for the graduate.
Basic laws of physics that a person should 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. We list the basic laws of physics that a person should know:
- Archimedes law (applies to the areas of hydro- as well as aerostatics). It implies that any body that has been immersed in a gaseous substance or in a liquid is affected by a kind of buoyancy force, which will certainly be directed vertically upward. This force is always numerically equal to the weight of the liquid or gas displaced by the body.
- Another formulation of this law is as follows: a body immersed in a gas or liquid will certainly lose as much weight as the mass of the liquid or gas into which it was immersed. This law became the basic postulate of the theory of swimming bodies.
- The law of gravity (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 greater the product of the masses of these bodies and, accordingly, the smaller the smaller the square of the distance between them.
These are the 3 basic laws of physics that everyone should know who wants to understand the mechanism of functioning of the surrounding world and the features 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 baggage of a person’s knowledge, regardless of his age and type of activity. They reflect the mechanism of existence of all of today's reality, and, in essence, are the only constant in a constantly changing world.
Basic laws and concepts of physics open up new possibilities for studying the world around us. Their knowledge helps to understand the mechanism of the existence of the Universe and the motion of all cosmic bodies. It does not turn us into just spies on daily events and processes, but allows us to be aware of 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 efficient way, making discoveries and thereby making his life more comfortable.
Summary
Some are forced to study in depth the basic laws of physics for the Unified State Examination, others according to their occupation, and some from scientific curiosity. Regardless of the purpose of studying this science, the benefit of the knowledge gained is difficult to overestimate. There is nothing more satisfying than an understanding of the basic mechanisms and laws of the existence of the surrounding world.
Do not remain indifferent - develop!