Movement is a directed straight line segment connecting the initial position of the body with its subsequent position. Acceleration is a value that characterizes the speed of change in speed. Uniform motion is a motion in which the body makes the same movements for any interval of time. Uniformly accelerated motion - motion in which the speed of the body for any equal intervals of time changes equally. Rotational motion Angular displacement - the angle of rotation of the radius vector in time dt Angular velocity - a vector quantity, the modulus of which is equal to the first time derivative of the angle of rotation of the radius vector. The rotation period T is the time of one complete rotation of the body around the axis of rotation. Angular acceleration is a vector quantity whose modulus is equal to the first time derivative of the angular velocity.

Dynamics

Conservation laws

Mechanical vibrations and waves

Molecular physics and thermodynamics.

Molecular physics

Aggregate states of matter

Fundamentals of thermodynamics

Electric field

DC Laws

Electric current in various environments

A magnetic field

The interaction between conductors with current, i.e., the interaction between moving electric charges, is called magnetic. The forces with which current-carrying conductors act on each other are called magnetic forces. A magnetic field is a special form of matter through which interaction between moving charged particles or bodies with a magnetic moment is carried out. Left hand rule: if the left hand is positioned so that the lines of magnetic induction enter the palm, and the outstretched four fingers coincide with the direction of the current in the conductor, then the bent thumb will indicate the direction of the force acting on the conductor with current placed in a magnetic field

It is natural and correct to be interested in the surrounding world and the laws of its functioning and development. 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. The 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 of and and thermodynamics are revealed to 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 action of which affects the life of everyone, and in many ways even provides it, about the features of matter, its structure and patterns 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 common 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 to be common to all nature. This is about

It implies that the energy of each closed system, when any phenomena occur in it, is necessarily conserved. 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, 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 interpreting the processes taking place in the surrounding world. Exploring them can be incredibly exciting. Therefore, in this article the basic laws of physics will be briefly considered, and in order to understand them deeper, it is important to pay full attention to them.

Mechanics

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

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

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

1. The principle of inertia says that any body is capable of being at rest or moving uniformly and rectilinearly only if no other bodies influence it in any way, or if they somehow compensate for 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 bodies of different sizes will also differ.
2. The main pattern of dynamics states that the greater the resultant of the forces that are currently acting on a given body, the greater the acceleration received by it. And, accordingly, the greater the body weight, the lower this indicator.
3. 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 necessarily have the opposite direction along the straight line that connects these bodies.
4. The principle of relativity states that all phenomena occurring under the same conditions in inertial frames of reference proceed in an absolutely identical way.

Thermodynamics

The school textbook, which reveals to students the basic laws ("Physics. Grade 7"), introduces them to the basics of thermodynamics. We will briefly review 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 determined that in a closed system, the external conditions for which are unchanged, an equilibrium state is established over time. And the processes that continue in it invariably compensate each other.

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

And the Gay-Lussac law (also called it states that for a gas of a certain mass under conditions of 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 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 work by it in relation to any acting external forces. It is this regularity that became the basis for the formation of a scheme for the operation of heat engines.

Another gas regularity is Charles' law. It states that the greater the pressure of a certain mass of an ideal gas, while maintaining a constant volume, the greater its temperature.

Electricity

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

Ampère's law, for example, states that conductors connected in parallel, through which current flows in the same direction, inevitably attract, and in the case of the opposite direction of current, respectively, repel. 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 a conductor that is currently conducting current. It is called so - 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 electric charges arising in any electrically isolated system is always conserved (becomes constant). Despite this, the named 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 equal to zero.

Coulomb's law is one of the fundamental in electrostatics. It 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 in an experimental way. It says that fixed point charges will certainly interact with each other with a force that is the higher, the greater the product of their magnitudes and, accordingly, the smaller, the smaller the square of the distance between the charges under consideration and the medium in which the described interaction occurs.

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 certain section of the circuit, the greater the voltage at its ends.

They call the principle that allows you to determine the direction in the conductor of a current moving under the influence of a magnetic field in a certain way. To do this, it is necessary to position the right hand so that the lines of magnetic induction figuratively touch the open palm, and extend the thumb in the direction 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 find out the exact location of the lines of magnetic induction of a straight conductor that conducts current at the moment. It works like this: place the thumb of the right hand in such a way that it points and figuratively grasp the conductor with the other four fingers. 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 process of operation of transformers, generators, electric motors. This law is as follows: in a closed circuit, the generated induction is the greater, the greater the rate of change of the magnetic flux.

Optics

The branch "Optics" also reflects a 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. Their study brings with it not just additional knowledge, but a better understanding of the surrounding reality. The main laws of physics that can be attributed to the field of study of optics are as follows:

1. Huynes principle. It is a method that allows you to efficiently determine at any given fraction of a second the exact position of the wave front. Its essence is as follows: all points that are in the path of the wave front in a certain fraction of a second, in fact, become sources of spherical waves (secondary) in themselves, while the placement of the wave front in the same fraction of a second is identical to the surface , which goes around 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 for resolving issues related to wave propagation. It helps to explain the elementary problems associated with the diffraction of light.
3. waves. It is equally used for reflection in the mirror. Its essence lies in the fact that both the falling beam and the one that was reflected, as well as the perpendicular constructed 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.
4. The principle of refraction of light. This is a change in the trajectory of an 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 propagation of light in them is different.
5. The law of rectilinear propagation of light. At its core, it is a law related to the field of geometric optics, and is as follows: in any homogeneous medium (regardless of its nature), light propagates strictly rectilinearly, along the shortest distance. This law simply and clearly explains the formation of a shadow.

Atomic and nuclear physics

The basic laws of quantum physics, as well as the fundamentals of atomic and nuclear physics, are studied in high school and higher education institutions.

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

These postulates refer to the standard school curriculum that studies the basic laws of physics (Grade 11). Their knowledge is mandatory for the graduate.

Basic laws of physics that a person should know

Some physical principles, although they belong 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 subject to a kind of buoyant force, 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 as follows: a body immersed in a gas or liquid will certainly lose as much weight as the mass of the liquid or gas in which it was immersed. This law became the basic postulate of the theory of floating 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 the greater, the greater the product of the masses of these bodies and, accordingly, the less, the smaller the square of the distance between them.

These are the 3 basic laws of physics that everyone who wants to understand the mechanism of the functioning of the surrounding world and the features of the processes occurring in it should know. It is quite easy to understand how they work.

The value of such knowledge

The basic laws of physics must be in the baggage of knowledge of a person, 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.

The basic laws, concepts of physics open up new opportunities for studying the world around us. Their knowledge helps to understand the mechanism of the existence of the Universe and the movement of all cosmic bodies. It turns us not just onlookers of 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 taking place around him, he gets the opportunity to control 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 exam, others - by occupation, and some - out of scientific curiosity. Regardless of the goals of studying this science, the benefits of the knowledge gained can hardly be overestimated. There is nothing more satisfying than understanding the basic mechanisms and laws of the existence of the surrounding world.

Don't be indifferent - develop!

Physical terms

Acoustics(from Greek. akustikos- auditory) - in a broad sense - a branch of physics that studies elastic waves from the lowest frequencies to the highest (1012–1013 Hz); in a narrow sense - the doctrine of sound. General and theoretical acoustics study the patterns of radiation and propagation of elastic waves in various media, as well as their interaction with the environment. The sections of acoustics include electroacoustics, architectural acoustics and building acoustics, atmospheric acoustics, geoacoustics, hydroacoustics, physics and technology of ultrasound, psychological and physiological acoustics, musical acoustics.

Astrospectroscopy- a branch of astronomy that studies the spectra of celestial bodies in order to determine the physical and chemical properties of these bodies, including the speeds of their movement, from the spectral characteristics.

Astrophysics- a branch of astronomy that studies the physical state and chemical composition of celestial bodies and their systems, interstellar and intergalactic media, as well as the processes occurring in them. The main sections of astrophysics: physics of planets and their satellites, physics of the Sun, physics of stellar atmospheres, interstellar medium, theory of the internal structure of stars and their evolution. Problems of the structure of superdense objects and related processes (capture of matter from the environment, accretion disks, etc.) and problems of cosmology are considered by relativistic astrophysics.

Atom(from Greek. atomos- indivisible) - the smallest particle of a chemical element that retains its properties. In the center of the atom is a positively charged nucleus, in which almost the entire mass of the atom is concentrated; electrons move around, forming electron shells, the dimensions of which (~108 cm) determine the dimensions of the atom. The nucleus of an atom is made up of protons and neutrons. The number of electrons in an atom is equal to the number of protons in the nucleus (the charge of all the electrons of the atom is equal to the charge of the nucleus), the number of protons is equal to the ordinal number of the element in the periodic system. Atoms can gain or donate electrons, becoming negatively or positively charged ions. The chemical properties of atoms are determined mainly by the number of electrons in the outer shell; Atoms combine chemically to form molecules. An important characteristic of an atom is its internal energy, which can only take certain (discrete) values ​​corresponding to the stable states of the atom, and changes only abruptly through a quantum transition. Absorbing a certain portion of energy, the atom goes into an excited state (to a higher energy level). From an excited state, an atom, emitting a photon, can go to a state with a lower energy (to a lower energy level). The level corresponding to the minimum energy of an atom is called the ground level, the rest are called excited. Quantum transitions determine the atomic absorption and emission spectra, individual for atoms of all chemical elements.

Atomic mass is the mass of an atom, expressed in atomic mass units. The atomic mass is less than the sum of the masses of the particles that make up the atom (protons, neutrons, electrons) by an amount determined by the energy of their interaction.

atomic nucleus- the positively charged central part of the atom, in which practically the entire mass of the atom is concentrated. Consists of protons and neutrons (nucleons). The number of protons determines the electric charge of the atomic nucleus and the atomic number Z of the atom in the Periodic system of elements. The number of neutrons is equal to the difference between the mass number and the number of protons. The volume of an atomic nucleus changes in proportion to the number of nucleons in the nucleus. In diameter, heavy atomic nuclei reach 10-12 cm. The density of nuclear matter is about 1014 g/cm3.

Aerolite- an obsolete name for a stone meteorite.

white dwarfs are compact stellar remnants of the evolution of low-mass stars. These objects are characterized by masses comparable to the mass of the Sun (2 1030 kg); radii comparable to the radius of the Earth (6400 km) and densities of the order of 106 g/cm3. The name "white dwarfs" is associated with the small size (compared to the typical sizes of stars) and the white color of the first discovered objects of this type, determined by their high temperature.

Block- a detail in the form of a wheel with a groove around the circumference for a thread, chain, rope. They are used in machines and mechanisms to change the direction of the force (fixed block), to obtain a gain in strength or path (movable block).

fireball- a large and exceptionally bright meteor.

Vacuum(from lat. vacuum- void) - the state of the gas at pressures p, lower than atmospheric. There are low vacuum (in vacuum devices and installations, it corresponds to the pressure range p above 100 Pa), medium (0.1 Pa< p < 100 Па), высокий (10-5 Па < p < 0,1 Па), и сверхвысокий (p < 10-5 Па). Понятие «вакуум» применимо к газу в откаченном объеме и в свободном пространстве, напр. к космосу.

Rotating moment is a measure of an external action that changes the angular velocity of a rotating body. Torque M rr is equal to the sum of the moments of all forces acting on the body about the axis of rotation and is related to the angular acceleration of the body e by the equality M vr = I e, where I is the moment of inertia of the body about the axis of rotation.

Universe- the entire existing material world, unlimited in time and space and infinitely diverse in the forms that matter takes in the process of its development. The Universe studied by astronomy is a part of the material world, which is accessible to research by astronomical means corresponding to the achieved level of development of science (sometimes this part of the Universe is called the Metagalaxy).

Computer Engineering – 1 ) a set of technical and mathematical means (computers, devices, devices, programs, etc.) used for mechanization and automation of computing and information processing processes. It is used in solving scientific and engineering problems associated with a large amount of calculations, in automatic and automated control systems, in accounting, planning, forecasting and economic evaluation, in making scientifically sound decisions, processing experimental data, in information retrieval systems, etc. . 2 ) A branch of technology involved in the development, manufacture and operation of computers, devices and devices.

Gas(French gas, from Greek. chaos- chaos) - the state of aggregation of a substance in which the kinetic energy of the thermal motion of its particles (molecules, atoms, ions) significantly exceeds the potential energy of interactions between them, and therefore, the particles move freely, uniformly filling in the absence of external fields the entire volume provided to them .

Galaxy(from Greek. galaktikos- milky) - a star system (spiral galaxy) to which the Sun belongs. The galaxy contains at least 1011 stars (with a total mass of 1011 solar masses), interstellar matter (gas and dust, whose mass is a few percent of the mass of all stars), cosmic rays, magnetic fields, radiation (photons). Most stars occupy a lenticular volume with a diameter of approx. 30 thousand pc, concentrating to the plane of symmetry of this volume (galactic plane) and to the center (flat subsystem of the Galaxy). A smaller part of the stars fills an almost spherical volume with a radius of approx. 15 thousand pc (spherical subsystem of the Galaxy), concentrating towards the center (core) of the Galaxy, which is located from the Earth in the direction of the constellation Sagittarius. The sun is located near the galactic plane at a distance of approx. 10 thousand pc from the center of the Galaxy. For a terrestrial observer, the stars concentrating towards the galactic plane merge into the visible picture of the Milky Way.

Helium(lat. Helium) is a chemical element with atomic number 2, atomic mass 4.002602. Belongs to the group of inert, or noble, gases (group VIIIA of the periodic system).

Hyperons(from Greek. hyper – above, above) – heavy unstable elementary particles with a mass greater than the mass of a nucleon (proton and neutron), having a baryon charge and a long lifetime compared to the "nuclear time" (~ 10-23 sec).

Gyroscope(from gyro... and... osprey) is a rapidly rotating rigid body, the axis of rotation of which can change its direction in space. A gyroscope has a number of interesting properties that are observed in rotating celestial bodies, in artillery shells, in a children's spinning top, in turbine rotors installed on ships, etc. Various devices or devices widely used in modern technology for automatically controlling the movement of aircraft are based on the properties of a gyroscope. , ships, missiles, torpedoes and other objects, to determine the horizon or geographic meridian, to measure the translational or angular speeds of moving objects (for example, missiles), and much more.

Globules– gas-dust formations with dimensions of several tenths of a parsec; are observed as dark spots against the background of light nebulae. Perhaps the globules are the regions where stars are born.

Gravity field(field of gravitation) - a physical field created by any physical objects; through the gravitational field, the gravitational interaction of bodies is carried out.

Pressure- a physical quantity characterizing the intensity of normal (perpendicular to the surface) forces F, with which one body acts on the surface S of another (for example, the foundation of a building on the ground, liquid on the vessel walls, etc.). If the forces are uniformly distributed along the surface, then the pressure is P = F/S. Pressure is measured in Pa or in kgf / cm2 (the same as at), as well as in mm Hg. st., atm, etc.

Dynamics(from the Greek dynamis - force) - a section of mechanics that studies the movement of bodies under the action of forces applied to them.

discreteness(from lat. discretus- divided, intermittent) - discontinuity; opposed to continuity. For example, a discrete change in a quantity over time is a change that occurs at certain intervals of time (jumps).

Dissociation(from lat. dissociation- separation) - the disintegration of a particle (molecule, radical, ion) into several simpler particles. The ratio of the number of particles that decayed during dissociation to their total number before decay is called the degree of dissociation. Depending on the nature of the impact that causes dissociation, there are thermal dissociation, photodissociation, electrolytic dissociation, dissociation under the action of ionizing radiation.

Inch(from goll. duim, lit. - thumb) - 1 ) submultiple unit of length in the system of English measures. 1 inch = 1/12 foot = 0.0254 m. 2 ) Russian odometric unit of length. 1 inch = 1/12 feet = 10 lines = 2.54 cm.

Liquid- the state of aggregation of a substance, combining the features of a solid state (conservation of volume, a certain tensile strength) and a gaseous state (shape variability). A liquid is characterized by a short-range order in the arrangement of particles (molecules, atoms) and a small difference in the kinetic energy of the thermal motion of molecules and their potential energy of interaction. The thermal motion of liquid molecules consists of oscillations around equilibrium positions and relatively rare jumps from one equilibrium position to another, which is associated with the fluidity of the liquid.

Law- a necessary, essential, stable, recurring relationship between phenomena in nature and society. The concept of "law" is related to the concept of essence. There are three main groups of laws: specific, or private (for example, the law of addition of velocities in mechanics); phenomena common to large groups (for example, the law of conservation and transformation of energy, the law of natural selection); general, or universal, laws. The knowledge of the law is the task of science.

Wien's radiation law– sets the distribution of energy in the spectrum of a black body depending on temperature. A special case of Planck's law of radiation for high frequencies. Bred in 1893 by V. Wine.

Planck's law of radiation– establishes the distribution of energy in the spectrum of a completely black body (equilibrium thermal radiation). Bred by M. Planck in 1900.

Radiation electromagnetic– the process of formation of a free electromagnetic field; radiation is also called the free electromagnetic field itself. Radiate rapidly moving charged particles (eg, bremsstrahlung, synchrotron radiation, radiation of variable dipoles, quadrupoles and higher-order multipoles). An atom and other atomic systems radiate during quantum transitions from excited states to states with lower energy.

Insulator(from the French isoler - to separate) - 1 ) a substance with a very high electrical resistivity (dielectric). 2 ) A device that prevents the formation of electrical contact and in many cases also provides a mechanical connection between parts of electrical equipment that are under different electrical potentials; made of dielectrics in the form of disks, cylinders, etc. 3 ) In radio engineering, insulators are called a segment of a short-circuited 2-wire or coaxial line, which has a high electrical resistance at a given frequency.

isotopes(from iso... and Greek. topos- place) - varieties of chemical elements in which the nuclei of atoms differ in the number of neutrons, but contain the same number of protons and therefore occupy the same place in the periodic system of elements. There are stable (stable) isotopes and radioactive isotopes. The term was proposed by F. Soddy in 1910.

Pulse – 1 ) a measure of mechanical motion (the same as the amount of motion). All forms of matter have momentum, including electromagnetic and gravitational fields; 2 ) impulse of force - a measure of the action of force over a certain period of time; is equal to the product of the average value of the force by the time of its action; 3 ) wave impulse - a single perturbation propagating in space or a medium, for example: a sound impulse - a sudden and rapidly disappearing increase in pressure; light pulse (a special case of electromagnetic) - short-term (0.01 s) emission of light by a source of optical radiation; 4 ) electrical impulse - a short-term deviation of voltage or current from a certain constant value.

Inertial frame of reference - a reference system in which the law of inertia is valid: a material point, when no forces act on it (or mutually balanced forces act), is at rest or uniform rectilinear motion.

ions(from Greek. ion- going) - electrically charged particles formed from an atom (molecule) as a result of the loss or addition of one or more electrons. Positively charged ions are called cations, negatively charged ions are called anions. The term was proposed by M. Faraday in 1834.

Dwarfs- stars of small sizes (from 1 to 0.01 solar radii) and low luminosities (from 1 to 10-4 solar luminosities) with a mass M from 1 to 0.1 solar masses. There are many eruptive stars among dwarfs. From ordinary, or red, dwarfs, white dwarfs differ sharply in their structure and properties.

Secondary quantization– a method for studying quantum systems of many or an infinite number of particles (or quasiparticles); is especially important in quantum field theory, which considers systems with a varying number of particles. In the method of quantization of the secondary state of the system, it is described using occupation numbers. The change of state is interpreted as the processes of birth and destruction of particles.

Quantum mechanics (wave mechanics) - a theory that establishes the method of description and the laws of motion of microparticles in given external fields; one of the main branches of quantum theory. Quantum mechanics made it possible for the first time to describe the structure of atoms and understand their spectra, establish the nature of the chemical bond, explain the periodic system of elements, and so on. Since the properties of macroscopic bodies are determined by the motion and interaction of the particles that form them, the laws of quantum mechanics underlie the understanding of most macroscopic phenomena. Thus, quantum mechanics made it possible to understand many properties of solids, to explain the phenomena of superconductivity, ferromagnetism, superfluidity, and much more; quantum mechanical laws underlie nuclear energy, quantum electronics, etc. In contrast to the classical theory, all particles in quantum mechanics act as carriers of both corpuscular and wave properties, which do not exclude, but complement each other. The wave nature of electrons, protons and other "particles" is confirmed by experiments on particle diffraction. The corpuscular-wave dualism of matter required a new approach to describing the state of physical systems and their changes over time. The state of a quantum system is described by a wave function, the square of the modulus of which determines the probability of a given state and, consequently, the probabilities for the values ​​of the physical quantities that characterize it; It follows from quantum mechanics that not all physical quantities can simultaneously have exact values ​​(see the Uncertainty Principle). The wave function obeys the superposition principle, which explains, in particular, particle diffraction. A distinctive feature of quantum theory is the discreteness of possible values ​​for a number of physical quantities: the energy of electrons in atoms, the angular momentum and its projection onto an arbitrary direction, etc.; in the classical theory all these quantities can change only continuously. A fundamental role in quantum mechanics is played by Planck's constant ћ - one of the main scales of nature, delimiting the areas of phenomena that can be described by classical physics (in these cases, j = 0 can be considered), from the areas for the correct interpretation of which quantum theory is necessary. Non-relativistic (pertaining to small particle velocities compared to the speed of light) quantum mechanics is a complete, logically consistent theory that is fully consistent with experience for that range of phenomena and processes in which there is no birth, annihilation, or mutual transformation of particles.

Quantum theory- combines quantum mechanics, quantum statistics and quantum field theory.

Quarks- hypothetical fundamental particles, of which, according to modern concepts, all hadrons consist (baryons - from three quarks, mesons - from a quark and an antiquark). Quarks have a spin of 1/2, a baryon charge of 1/3, electric charges of -2/3 and +1/3 of the proton's charge, and a specific quantum number "color". Experimentally (indirectly) discovered 6 types ("flavors") of quarks: u, d, s, c, b, t. They were not observed in the free state.

Kinetic energy is the energy of the mechanical system, which depends on the speed of movement of its constituent parts. In classical mechanics, the kinetic energy of a material point of mass m moving at a speed v, is equal to 1/2 mv 2.

Oxygen(lat. Ohygenium) is a chemical element with atomic number 8, atomic mass 15.9994. In the periodic system of elements, Mendeleev is located in the second period in the VIA group.

classical mechanics- studies the movement of macroscopic bodies with speeds that are small compared to the speed of light, based on Newton's laws.

Fluctuations - movements (changes of state) with varying degrees of repeatability. When the pendulum oscillates, its deviations in one direction and the other from the vertical position are repeated. When the spring pendulum oscillates – weight hanging on a spring – its deviations up and down from some average position are repeated. When oscillating in an electrical circuit with capacitance C and inductance L, the magnitude and sign of the charge are repeated q on each plate of the capacitor. Pendulum swings occur because: 1) gravity returns the deflected pendulum to its equilibrium position; 2) having returned to the equilibrium position, the pendulum, having a speed, continues to move (by inertia) and again deviates from the equilibrium position in the direction opposite to the one from which it came.

Colorimetry(from lat. color- color and Greek. metreo- I measure), methods for measuring and quantifying color are based on determining the color coordinates in the selected system of 3 primary colors.

Coma- distortion of the image in optical systems, due to which the point of the object takes the form of an asymmetric spot.

Comets(from Greek. cometes, lit. - long-haired), the bodies of the solar system move in highly elongated orbits, at considerable distances from the sun they look like faintly luminous oval spots, and as they approach the sun they have a “head” and “tail”. The central part of the head is called the nucleus. The diameter of the core is 0.5-20 km, the mass is 1011-1019 kg, the core is an icy body - a conglomerate of frozen gases and dust particles. The tail of a comet consists of molecules (ions) of gases and dust particles escaping from the nucleus under the action of sunlight; the length of the tail can reach tens of millions of kilometers. The most famous periodic comets are Halley (period R 76 years old), Enke ( R 3.3 years), Schwassmann - Wachmann (the comet's orbit lies between the orbits of Jupiter and Saturn). While passing through perihelion in 1986, Halley's comet was examined by spacecraft.

Compton Effect- discovered by A. Compton (1922) elastic scattering of electromagnetic radiation of small wavelengths (X-ray and gamma radiation) on free electrons, accompanied by an increase in the wavelength l. The Compton effect contradicts the classical theory, according to which l should not change during such scattering. The Compton effect confirmed the correctness of quantum ideas about electromagnetic radiation as a stream of photons and can be considered as an elastic collision of two "particles" - a photon and an electron, in which the photon transfers part of its energy (and momentum) to the electron, as a result of which its frequency decreases, and l increases .

Convection(from lat. convection- bringing, delivery) - the movement of macroscopic parts of the medium (gas, liquid), leading to the transfer of mass, heat, and other physical quantities. There are natural (free) convection caused by the inhomogeneity of the medium (temperature and density gradients), and forced convection caused by external mechanical action on the medium. The formation of clouds is associated with convection in the Earth's atmosphere, and granulation is associated with convection on the Sun.

Electric circuit(circuit of an electrical circuit) - any closed path passing through several branches of an electrical circuit. Sometimes the term "electrical circuit" is used as a synonym for the term "oscillating circuit".

Coriolis force(named after the French scientist G. Corey-olis) – one of the forces of inertia introduced to take into account the influence of the rotation of a moving frame of reference on the relative motion of a material point. The Coriolis force is equal to the product of the mass of a point and its Coriolis acceleration and is directed opposite to this acceleration.

Coefficient(from lat. co- jointly and efficiency- producing) - a multiplier, usually expressed in numbers. If the product contains one or more variable (or unknown) quantities, then the coefficient for them is also called the product of all constants, including those expressed by letters. Many coefficients in physical laws have special names, for example, friction coefficient, light absorption coefficient.

red giants- stars with low effective temperatures (3000-4000 K) and very large radii (10-100 times the radius of the Sun). The maximum radiation energy falls on the red and infrared parts of the spectrum. The luminosity of red giants is approximately 100 times greater than the luminosity of the Sun.

Lagrange equations -1 ) in hydromechanics - the equations of motion of a liquid medium, written in Lagrange variables, which are the coordinates of the particles of the medium. From the Lagrange equation, the law of motion of particles of the medium is determined in the form of dependences of coordinates on time, and trajectories, velocities and accelerations of particles are found from them. 2 ) In general mechanics, equations used to study the motion of a mechanical system, in which parameters that are independent of each other are chosen for the quantities that determine the position of the system, are called generalized coordinates. First obtained by J. Lagrange in 1760

Magnetism(from Greek. magnetis– magnet) – 1 ) a branch of physics that studies the interaction of moving electrically charged particles (bodies) or particles (bodies) with a magnetic moment, carried out by a magnetic field. 2 ) The general name of the manifestations of this interaction. Elementary particles (electrons, protons, etc.), electric currents and magnetized bodies with a magnetic moment participate in magnetic interactions. For elementary particles, the magnetic moment can be spin and orbital. The magnetism of atoms of molecules and macroscopic bodies is ultimately determined by the magnetism of elementary particles. Depending on the nature of the interaction of particles-carriers of the magnetic moment, substances can exhibit ferromagnetism, ferrimagnetism, antiferromagnetism, paramagnetism, diamagnetism, and other types of magnetism.

A magnetic field- one of the forms of the electromagnetic field. The magnetic field is created by moving electric charges and spin magnetic moments of atomic carriers of magnetism (electrons, protons, etc.). A complete description of electric and magnetic fields and their relationship is given by Maxwell's equations.

Weight- one of the main physical characteristics of matter, which determines its inert and gravitational properties. In classical mechanics, mass is equal to the ratio of the force acting on the body to the acceleration it causes (Newton's 2nd law) - in this case, the mass is called inertial; in addition, the mass creates a gravitational field - gravitational, or heavy, mass. Inertial and heavy masses are equal to each other (equivalence principle).

Mesoatom- an atom-like system in which the forces of electrostatic attraction bind the positive nucleus with one (or several) negatively charged muons (muonic atom) or hadrons (hadron atom). The mesoatom can also contain electrons.

meteorites- small bodies of the solar system that fall to Earth from interplanetary space. The mass of one of the largest meteors - Goba meteorite - approx. 60,000 kg. There are iron and stone meteorites.

Method(from Greek. methodos- the path of research, theory, teaching) - a way to achieve a goal, solve a specific problem; a set of techniques or operations of practical or theoretical development (cognition) of reality.

Mechanics(from Greek mechanike - the art of building machines) - the science of the mechanical movement of material bodies (i.e., changing the relative position of bodies or their parts in space over time) and the interactions between them. Classical mechanics is based on Newton's laws. The methods of mechanics study the motions of any material bodies (except for microparticles) with speeds that are small compared to the speed of light. Movements of bodies with velocities close to the speed of light are considered in the theory of relativity, and the movement of microparticles - in quantum mechanics. Depending on the motion of which objects is considered, one distinguishes between the mechanics of a material point and systems of material points, the mechanics of a solid body, and the mechanics of a continuous medium. Mechanics is divided into statics, kinematics and dynamics. The laws of mechanics are used to calculate machines, mechanisms, building structures, vehicles, spacecraft, etc. The founders of mechanics - G. Galileo, I. Newton and others.

microparticles– particles of very small mass; these include elementary particles, atomic nuclei, atoms, molecules.

Milky Way– 1 ) a dimly luminous band crossing the starry sky. It is a huge number of visually indistinguishable stars concentrating towards the main plane of the Galaxy. The Sun is located near this plane, so that most of the stars of the Galaxy are projected onto the celestial sphere within a narrow band - the Milky Way. 2 ) Actually the name of the Galaxy.

Molecule(novolat. molecule, reduce. from lat. moles- mass) - a microparticle formed from atoms and capable of independent existence. It has a constant composition of its constituent atomic nuclei and a fixed number of electrons and has a set of properties that make it possible to distinguish molecules of one type from molecules of another. The number of atoms in a molecule can be different: from two to hundreds of thousands (eg, in a protein molecule); the composition and arrangement of atoms in a molecule is conveyed by the chemical formula. The molecular structure of a substance is established by X-ray diffraction analysis, electron diffraction, mass spectrometry, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and other methods.

Molecular mass(molecular weight) is the mass of a molecule, expressed in atomic mass units. Almost equal to the sum of the masses of all the atoms that make up the molecule. Molecular weight values ​​are used in chemical, physical and chemical engineering calculations.

Moment of inertia- a quantity that characterizes the distribution of masses in the body and, along with the mass, is a measure of the inertia of the body during non-translational motion.

Moment of momentum(kinetic moment, angular momentum, angular momentum) - a measure of the mechanical movement of a body or system of bodies relative to any center (point) or axis. To calculate moment of momentum To material point (body), the same formulas are valid as for calculating the moment of force, if we replace the force vector in them with the momentum vector mv, in particular K 0 = [ r× mv]. The sum of the moments of the momentum of all points of the system about the center (axis) is called the main moment of the momentum of the system (kinetic moment) about this center (axis). With the rotational motion of a rigid body, the main moment of momentum about the axis of rotation z body is expressed by the product of the moment of inertia I z to the angular velocity w of the body, i.e. To Z= I zw.

Muons– unstable elementary particles with spin 1/2, lifetime 2.210-6 sec and a mass approximately 207 times the mass of an electron.

The session is approaching, and it's time for us to move from theory to practice. Over the weekend, we sat down and thought that many students would do well to have a collection of basic physics formulas handy. Dry formulas with explanation: short, concise, nothing more. A very useful thing when solving problems, you know. Yes, and in the exam, when exactly what was cruelly memorized the day before can “jump out” of my head, such a selection will serve you well.

Most of the tasks are usually given in the three most popular sections of physics. it Mechanics, thermodynamics and Molecular physics, electricity. Let's take them!

Basic formulas in physics dynamics, kinematics, statics

Let's start with the simplest. Good old favorite rectilinear and uniform movement.

Kinematic formulas:

Of course, let's not forget about the movement in a circle, and then move on to the dynamics and Newton's laws.

After the dynamics, it's time to consider the conditions for the equilibrium of bodies and liquids, i.e. statics and hydrostatics

Now we give the basic formulas on the topic "Work and energy". Where would we be without them!

Basic formulas of molecular physics and thermodynamics

Let's finish the section of mechanics with formulas for vibrations and waves and move on to molecular physics and thermodynamics.

Efficiency, Gay-Lussac's law, the Clapeyron-Mendeleev equation - all these sweet formulas are collected below.

By the way! There is a discount for all our readers 10% on the .

Basic formulas in physics: electricity

It's time to move on to electricity, although thermodynamics loves it less. Let's start with electrostatics.

And, to the drum roll, we finish with the formulas for Ohm's law, electromagnetic induction and electromagnetic oscillations.

That's all. Of course, a whole mountain of formulas could be given, but this is useless. When there are too many formulas, you can easily get confused, and then completely melt the brain. We hope that our cheat sheet of basic formulas in physics will help you solve your favorite problems faster and more efficiently. And if you want to clarify something or have not found the formula you need: ask the experts student service. Our authors keep hundreds of formulas in their heads and click tasks like nuts. Contact us, and soon any task will be "too tough" for you.

Examination tickets in physics 2006-2007 ac. year

Grade 9

Ticket number 1.mechanical movement. Path. Speed, Acceleration

mechanical movement- change in the position of the body in space relative to other bodies over time.

Path- the length of the trajectory along which the body moves for some time. Denoted by the letter s and measured in meters (m). Calculated according to the formula

Speed is a vector quantity equal to the ratio of the path to the time for which this path has been traveled. Determines both the speed of movement and its direction at a given time. Denoted by a letter and measured in meters per second (). Calculated according to the formula

Acceleration with uniformly accelerated motion is a vector quantity equal to the ratio of the change in speed to the time interval during which this change occurred. Determines the rate of change of speed in magnitude and direction. Denoted by letter a or and is measured in meters per second squared (). Calculated according to the formula

Ticket number 2.The phenomenon of inertia. Newton's first law. Strength and composition of forces. Newton's second law

The phenomenon of maintaining the speed of a body in the absence of the action of other bodies is called inertia.

Newton's first law: there are frames of reference with respect to which bodies keep their speed unchanged if they are not acted upon by other bodies.

Frames of reference where the law of inertia is satisfied are called inert.

Frames of reference where the law of inertia is not fulfilled - non-inert.

Strength- vector quantity. And it is a measure of the interaction of bodies. Denoted by letter F or and is measured in newtons (N)

A force that produces the same effect on a body as several simultaneously acting forces is called resultant of these forces.

The resultant of forces directed along one straight line in one direction is directed in the same direction, and its module is equal to the sum of the modules of the component forces.

The resultant of forces directed along one straight line in opposite directions is directed towards the greater force in absolute value, and its module is equal to the difference between the modules of the component forces.

The greater the resultant of the forces applied to the body, the greater the acceleration of the body.

When the force is halved, the acceleration is also halved, i.e.

Means, the acceleration with which a body of constant mass moves is directly proportional to the force applied to this body, as a result of which acceleration occurs.

When the body weight is doubled, the acceleration is halved, i.e.

Means, the acceleration with which a body moves with a constant force is inversely proportional to the mass of that body.

The quantitative relationship between body mass, acceleration, and the resultant of the forces applied to the body is called Newton's second law.

Second Newton's law: acceleration of the body is directly proportional to the resultant forces applied to the body and inversely proportional to its mass.

Mathematically, Newton's second law is expressed by the formula:

Ticket number 3. Newton's third law. Pulse. Law of conservation of momentum. Explanation of jet propulsion based on the law of conservation of momentum

Newton's third law: the forces with which two bodies act on each other are equal in magnitude and opposite in direction.

Mathematically, Newton's third law is expressed as follows:

body momentum- a vector quantity equal to the product of the mass of the body and its speed. It is denoted by a letter and is measured in kilograms per meters per second (). Calculated according to the formula

law of conservation of momentum: the sum of the momenta of the bodies before the interaction is equal to the sum after the interaction. Let's consider jet propulsion based on the motion of a balloon with a jet of air coming out of it. According to the law of conservation of momentum, the total momentum of a system consisting of two bodies must remain the same as it was before the start of the outflow of air, i.e. equal to zero. Therefore, the ball begins to move in the direction opposite to the air jet with the same speed that its momentum is equal to the modulus of the air jet momentum.

Ticket number 4.Gravity. Free fall. Acceleration of gravity. Law of gravity

Gravity- the force with which the Earth attracts the body to itself. Denoted or

Free fall- the movement of bodies under the influence of gravity.

In a given place on the Earth, all bodies, regardless of their masses and other physical characteristics, free fall with the same acceleration. This acceleration is called free fall acceleration and is denoted by the letter or . It

The law of universal gravitation: any two bodies are attracted to each other with a force directly proportional to the mass of each of them and inversely proportional to the square of the distance between them.

G \u003d 6.67 10 -11 N m 2 / kg 2

G - Gravitational constant

Ticket number 5. Elastic force. Explanation of the device and principle of operation of the dynamometer. Friction force. Friction in nature and technology

The force that arises in the body as a result of its deformation and tends to return the body to its original position is called elastic force. Designated . It is found according to the formula

Dynamometer- a device for measuring force.

The main part of the dynamometer is a steel spring, which is given a different shape depending on the purpose of the device. The device of the simplest dynamometer is based on the comparison of any force with the elastic force of the spring.

When one body comes into contact with another, an interaction occurs that prevents their relative motion, which is called friction. And the force that characterizes this interaction is called friction force. There is static friction, sliding friction and rolling friction.

Without the friction of rest, neither people nor animals could walk on the earth, because. When we walk, we push off the ground with our feet. If there were no friction, objects would slip out of the hands. The force of friction stops the car when braking, but without static friction, it would not be able to start moving. In many cases, friction is harmful and must be dealt with. To reduce friction, the contact surfaces are made smooth, and a lubricant is introduced between them. To reduce the friction of the rotating shafts of machines and machine tools, they are supported on bearings.

Ticket number 6. Pressure. Atmosphere pressure. Pascal's law. Law of Archimedes

The value equal to the ratio of the force acting perpendicular to the surface to the area of ​​this surface is called pressure. It is denoted by the letter or and is measured in pascals (Pa). Calculated according to the formula

Atmosphere pressure- this is the pressure of the entire thickness of the air on the earth's surface and the bodies located on it.

Atmospheric pressure equal to the pressure of a column of mercury 760 mm high at a temperature is called normal atmospheric pressure.

Normal atmospheric pressure is 101300Pa = 1013hPa.

Every 12m the pressure decreases by 1mm. rt. Art. (or by 1.33hPa)

Pascal's law: the pressure exerted on a liquid or gas is transmitted to any point equally in all directions.

Archimedes' law: a body immersed in a liquid (or gas, or plasma) is subjected to a buoyant force (called the Archimedes force)

where ρ is the density of the liquid (gas), is the acceleration of free fall, and V is the volume of the submerged body (or the part of the volume of the body below the surface). The buoyant force (also called the Archimedean force) is equal in absolute value (and opposite in direction) to the force of gravity acting on the volume of liquid (gas) displaced by the body, and is applied to the center of gravity of this volume.

It should be noted that the body must be completely surrounded by the liquid (or intersected by the surface of the liquid). So, for example, the law of Archimedes cannot be applied to a cube that lies at the bottom of the tank, hermetically touching the bottom.

Ticket number 7.Force work. Kinetic and potential energy. Law of conservation of mechanical energy

Mechanical work is done only when a force acts on the body and it moves.

mechanical work directly proportional to the applied force and directly proportional to the distance traveled. It is denoted by the letter or and is measured in joules (J). Calculated according to the formula

Energy - a physical quantity showing how much work a body can do. Energy is measured in joules (J).

Potential energy called energy, which is determined by the mutual position of interacting bodies or parts of the same body. Indicated by the letter or . Calculated according to the formula

The energy possessed by a body as a result of its motion is called kinetic energy. Indicated by the letter or . Calculated according to the formula

The law of conservation of mechanical energy:

In the absence of forces such as friction, mechanical energy does not arise from nothing and cannot disappear anywhere.

Ticket number 8.Mechanical vibrations. mechanical waves. Sound.Fluctuations in nature and technology

A movement that repeats itself after a certain period of time is called oscillatory.

Oscillations that occur only due to the initial supply of energy are called free vibrations Physics The concept of time in classical thermodynamics Abstract >> Philosophy

He puts time first major concepts physics, followed by space, place... ideas about space is introduced in physics high energy concept physical vacuum as a kind of...