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1 BASIC FORMULA IN PHYSICS FOR STUDENTS OF TECHNICAL UNIVERSITIES.. Physical foundations mechanics. Instantaneous speed dr r- radius-vector of a material point, t- time, Module of instantaneous speed s- distance along the trajectory, Path length Acceleration: instantaneous tangential normal total τ- unit vector tangent to the trajectory; R is the radius of curvature of the trajectory, n is the unit vector of the main normal. ANGULAR SPEED ds = S t t t d a d a a n n R a a a, n a a a n d φ- angular displacement. Angular acceleration d.. Relationship between linear and.. angular quantities s= φr, υ= ωr, a τ = εr, a n = ω R.3. Impulse.4. of a material point p is the mass of a material point. The basic equation of the dynamics of a material point (Newton's second law)

2 a dp Fi, Fi Momentum conservation law for an isolated mechanical system Radius-vector of the center of mass Dry friction force μ- coefficient of friction, N- force of normal pressure. Elasticity force k- coefficient of elasticity (stiffness), Δl- deformation..4.. Gravitational force F G r and - particle masses, G-gravitational constant, r- distance between particles. Work of force A FdS da Power N F Potential energy: k(l) of an elastically deformed body P= gravitational interaction of two particles P= G r of the body in a uniform gravitational field g- intensity gravitational field(acceleration of free fall), h- distance from the zero level. P=gh

3.4.4. Gravity tension.4.5. Earth's field g \u003d G (R h) 3 Earth's mass, R 3 - Earth's radius, h - distance from the Earth's surface. Potential of the Earth's gravitational field 3 Kinetic energy of a material point φ= G T= (R 3 3 h) p The law of conservation of mechanical energy for a mechanical system E=T+P=onst Moment of inertia of a material point J=r r- distance to the axis of rotation. Moments of inertia of bodies with a mass about an axis passing through the center of mass: a thin-walled cylinder (ring) of radius R, if the axis of rotation coincides with the axis of the cylinder J o \u003d R, a solid cylinder (disk) of radius R, if the axis of rotation coincides with the axis of the cylinder J o \u003d R ball of radius R J o \u003d 5 R thin rod of length l, if the axis of rotation is perpendicular to the rod J o \u003d l

4 J is the moment of inertia about a parallel axis passing through the center of mass, d is the distance between the axles. Moment of force acting on a material point relative to the origin r-radius-vector of the point of force application Moment of momentum of the system.4.8. about the Z axis r F N.4.9. L z J iz iz i.4.. Basic equation of dynamics.4.. of rotational motion Law of conservation of angular momentum for an isolated system Work with rotational motion dl, J.4.. Σ J i ω i =onst A d Kinetic energy of a rotating body J T= L J Relativistic contraction of the length l l lо is the length of the body at rest c is the speed of light in vacuum. Relativistic time dilation t t t about proper time. Relativistic mass o rest mass Rest energy of the particle E o = o c

5.4.3. Total energy relativistic.4.4. particles.4.5. E=.4.6. Relativistic impulse Р=.4.7. Kinetic energy.4.8. relativistic particle.4.9. T \u003d E- E o \u003d Relativistic relationship between total energy and momentum E \u003d p c + E o The law of addition of velocities in relativistic mechanics and and and - velocities in two inertial frames of reference moving relative to each other with a speed υ coinciding in direction with u (sign -) or opposite to it (sign +) u u u Physics of mechanical oscillations and waves. The displacement of the oscillating material point s Aos(t) A is the amplitude of the oscillation, is the natural cyclic frequency, φ o is the initial phase. Cyclic frequency T

6 T oscillation period - frequency Velocity of an oscillating material point Acceleration of an oscillating material point Kinetic energy of a material point making harmonic oscillations v ds d s a v T Potential energy of a material point making harmonic oscillations Ï kx Stiffness coefficient (elasticity factor) Total energy of a material point making harmonic oscillations A sin(t) dv E T П A os(t) A A A sin (t) os (t) d s Differential equation s free harmonic sustained oscillations of magnitude s d s ds Differential equation s of free damped oscillations of magnitude s, - damping coefficient A(t) T Logarithmic decrement ln T A(T t) of damping, relaxation time d s ds Differential equation s F ost , k

7 physical T J, gl - mass of the pendulum, k - spring stiffness, J - moment of inertia of the pendulum, g - free fall acceleration, l - distance from the point of suspension to the center of mass. The equation plane wave propagating in the direction of the Ox axis, v is the speed of wave propagation Wavelength T is the period of the wave, v is the speed of wave propagation, the oscillation frequency Wave number , T- thermodynamic temperature, M- molar mass of gas x (x, t) Aos[ (t) ] v v T v vt v RT Molecular physics and thermodynamics..4.. Amount of substance N N A, N- number of molecules, N A - Avogadro's constant is the mass of a substance M is the molar mass. Clapeyron-Mendeleev equation p = ν RT,

8 p - gas pressure, - its volume, R - molar gas constant, T - thermodynamic temperature. The equation of the molecular-kinetic theory of gases Р= 3 n<εпост >= 3 no<υ кв >n is the concentration of molecules,<ε пост >is the average kinetic energy of the translational motion of the molecule. o is the mass of the molecule<υ кв >- RMS speed. Average energy of a molecule<ε>= i kt i - number of degrees of freedom k - Boltzmann's constant. Internal energy of an ideal gas U= i νrt Molecular velocities: root mean square<υ кв >= 3kT = 3RT ; arithmetic mean<υ>= 8 8RT = kt ; most likely<υ в >= Average free length kt = RT ; molecular range d-effective diameter of the molecule Average number of collisions (d n) of the molecule per unit time z d n v

9 Distribution of molecules in a potential field of forces P-potential energy of a molecule. Barometric formula p - gas pressure at height h, p - gas pressure at a level taken as zero, - mass of the molecule, Fick's law of diffusion j - mass flow density, n n exp kt gh p p exp kt j d ds d =-D dx d - density gradient, dx D-diffusion coefficient, ρ-density, d-gas mass, ds-elementary area perpendicular to the Ox axis. Fourier thermal conductivity law j - heat flux density, Q j Q dq ds dt =-æ dx dt - temperature gradient, dx æ - thermal conductivity coefficient, Internal friction force η - dynamic viscosity coefficient, dv df ds dz d - velocity gradient, dz Coefficient diffusion D= 3<υ><λ>Coefficient of dynamic viscosity (internal friction) v 3 D Coefficient of thermal conductivity æ = 3 сv ρ<υ><λ>=ηс v

10 s v specific isochoric heat capacity, Molar heat capacity of ideal gas isochoric isobaric First law of thermodynamics i C v R i C p R dq=du+da, da=pd, du=ν C v dt -)= ν R(T -T) isothermal p А= ν RT ln = ν RT ln p adiabatic A C T T) γ=с р /С v (RT A () p A= () Poisson's equations Efficiency of the Carnot cycle. 4.. Q n and T n - the amount of heat received from the heater and its temperature; Q x and T x - the amount of heat transferred to the refrigerator and its temperature. Change in entropy during the transition of the system from state to state Р γ =onst T γ- =onst T γ r - γ =onst Qí Q Q S S í õ Tí T T dq T í õ


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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 with 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 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 affect 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 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 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, have general character 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 an unyielding logical definition rule that in a closed system, 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 are studied. electric current, as well as other nuances.

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. However, general 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 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 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, you need to position the brush 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 effective method resolution of issues related to the propagation of waves. 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 refraction.
  4. The principle of refraction of light. This is a change in trajectory 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

Basic Laws quantum physics, as well as the basics of atomic and nuclear physics are studied in high school high school and higher educational 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 radiation 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 belong to the standard school curriculum studying 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). He implies that any body that has been immersed in gaseous substance or into a liquid, there is 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 space 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!

Cheat sheet with formulas in physics for the exam

and not only (may need 7, 8, 9, 10 and 11 classes).

For starters, a picture that can be printed in a compact form.

Mechanics

  1. Pressure P=F/S
  2. Density ρ=m/V
  3. Pressure at the depth of the liquid P=ρ∙g∙h
  4. Gravity Ft=mg
  5. 5. Archimedean force Fa=ρ w ∙g∙Vt
  6. The equation of motion for uniformly accelerated motion

X=X0 + υ 0∙t+(a∙t 2)/2 S=( υ 2 -υ 0 2) /2а S=( υ +υ 0) ∙t /2

  1. Velocity equation for uniformly accelerated motion υ =υ 0 +a∙t
  2. Acceleration a=( υ -υ 0)/t
  3. Circular speed υ =2πR/T
  4. Centripetal acceleration a= υ 2/R
  5. Relationship between period and frequency ν=1/T=ω/2π
  6. Newton's II law F=ma
  7. Hooke's law Fy=-kx
  8. Law of universal gravitation F=G∙M∙m/R 2
  9. The weight of a body moving with acceleration a P \u003d m (g + a)
  10. The weight of a body moving with acceleration a ↓ P \u003d m (g-a)
  11. Friction force Ffr=µN
  12. Body momentum p=m υ
  13. Force impulse Ft=∆p
  14. Moment M=F∙ℓ
  15. Potential energy of a body raised above the ground Ep=mgh
  16. Potential energy of elastically deformed body Ep=kx 2 /2
  17. Kinetic energy of the body Ek=m υ 2 /2
  18. Work A=F∙S∙cosα
  19. Power N=A/t=F∙ υ
  20. Efficiency η=Ap/Az
  21. Oscillation period of the mathematical pendulum T=2π√ℓ/g
  22. Oscillation period of a spring pendulum T=2 π √m/k
  23. The equation harmonic vibrationsХ=Хmax∙cos ωt
  24. Relationship of the wavelength, its speed and period λ= υ T

Molecular physics and thermodynamics

  1. Amount of substance ν=N/ Na
  2. Molar mass M=m/v
  3. Wed. kin. energy of monatomic gas molecules Ek=3/2∙kT
  4. Basic equation of MKT P=nkT=1/3nm 0 υ 2
  5. Gay-Lussac law (isobaric process) V/T =const
  6. Charles' law (isochoric process) P/T =const
  7. Relative humidity φ=P/P 0 ∙100%
  8. Int. ideal energy. monatomic gas U=3/2∙M/µ∙RT
  9. Gas work A=P∙ΔV
  10. Boyle's law - Mariotte (isothermal process) PV=const
  11. The amount of heat during heating Q \u003d Cm (T 2 -T 1)
  12. The amount of heat during melting Q=λm
  13. The amount of heat during vaporization Q=Lm
  14. The amount of heat during fuel combustion Q=qm
  15. The equation of state for an ideal gas is PV=m/M∙RT
  16. First law of thermodynamics ΔU=A+Q
  17. Efficiency of heat engines η= (Q 1 - Q 2) / Q 1
  18. Ideal efficiency. engines (Carnot cycle) η \u003d (T 1 - T 2) / T 1

Electrostatics and electrodynamics - formulas in physics

  1. Coulomb's law F=k∙q 1 ∙q 2 /R 2
  2. tension electric field E=F/q
  3. Email tension. fields point charge E=k∙q/R2
  4. Surface charge density σ = q/S
  5. Email tension. fields of the infinite plane E=2πkσ
  6. Dielectric constant ε=E 0 /E
  7. Potential energy of interaction. charges W= k∙q 1 q 2 /R
  8. Potential φ=W/q
  9. Point charge potential φ=k∙q/R
  10. Voltage U=A/q
  11. For a uniform electric field U=E∙d
  12. Electric capacity C=q/U
  13. Capacitance of a flat capacitor C=S∙ ε ∙ε 0/d
  14. Energy of a charged capacitor W=qU/2=q²/2С=CU²/2
  15. Current I=q/t
  16. Conductor resistance R=ρ∙ℓ/S
  17. Ohm's law for the circuit section I=U/R
  18. The laws of the last compounds I 1 \u003d I 2 \u003d I, U 1 + U 2 \u003d U, R 1 + R 2 \u003d R
  19. Parallel laws. conn. U 1 \u003d U 2 \u003d U, I 1 + I 2 \u003d I, 1 / R 1 + 1 / R 2 \u003d 1 / R
  20. Electric current power P=I∙U
  21. Joule-Lenz law Q=I 2 Rt
  22. Ohm's law for a complete chain I=ε/(R+r)
  23. Short circuit current (R=0) I=ε/r
  24. Magnetic induction vector B=Fmax/ℓ∙I
  25. Ampere Force Fa=IBℓsin α
  26. Lorentz force Fл=Bqυsin α
  27. Magnetic flux Ф=BSсos α Ф=LI
  28. Law of electromagnetic induction Ei=ΔФ/Δt
  29. EMF of induction in moving conductor Ei=Вℓ υ sinα
  30. EMF of self-induction Esi=-L∙ΔI/Δt
  31. The energy of the magnetic field of the coil Wm \u003d LI 2 / 2
  32. Oscillation period count. contour T=2π ∙√LC
  33. Inductive reactance X L =ωL=2πLν
  34. Capacitance Xc=1/ωC
  35. The current value of the current Id \u003d Imax / √2,
  36. RMS voltage Ud=Umax/√2
  37. Impedance Z=√(Xc-X L) 2 +R 2

Optics

  1. The law of refraction of light n 21 \u003d n 2 / n 1 \u003d υ 1 / υ 2
  2. Refractive index n 21 =sin α/sin γ
  3. Thin lens formula 1/F=1/d + 1/f
  4. Optical power of the lens D=1/F
  5. max interference: Δd=kλ,
  6. min interference: Δd=(2k+1)λ/2
  7. Differential grating d∙sin φ=k λ

The quantum physics

  1. Einstein's formula for the photoelectric effect hν=Aout+Ek, Ek=U ze
  2. Red border of the photoelectric effect ν to = Aout/h
  3. Photon momentum P=mc=h/ λ=E/s

Physics of the atomic nucleus

  1. Law radioactive decay N=N 0 ∙2 - t / T
  2. Bond energy atomic nuclei

Mechanics
1. Pressure P=F/S
2. Density ρ=m/V
3. Pressure at the depth of the liquid P=ρ∙g∙h
4. Gravity Ft=mg
5. Archimedean force Fa=ρzh∙g∙Vt
6. Equation of motion for uniformly accelerated motion
m(g+a)
m(ga)
X=X0+υ0∙t+(a∙t2)/2 S= (υ2υ0
2) /2а S= (υ+υ0) ∙t /2
7. Velocity equation for uniformly accelerated motion υ=υ0+a∙t
8. Acceleration a=(υυ 0)/t
9. Speed ​​​​when moving along a circle υ \u003d 2πR / T
10. Centripetal acceleration a=υ2/R
11. Relationship between period and frequency ν=1/T=ω/2π
12.
Newton's II law F=ma
13. Hooke's law Fy=kx
14. Law of universal gravitation F=G∙M∙m/R2
15. The weight of a body moving with acceleration a P =
16. The weight of a body moving with acceleration a P =
17. Friction force Ffr=µN
18. Momentum of the body p=mυ
19. Force impulse Ft=∆p
20. Moment of force M=F∙?
21. Potential energy of a body raised above the ground Ep=mgh
22. Potential energy of elastically deformed body Ep=kx2/2
23. Kinetic energy of the body Ek=mυ2/2
24. Job A=F∙S∙cosα
25. Power N=A/t=F∙υ
26. Efficiency η=Ap/Az
27. Oscillation period of a mathematical pendulum T=2 √?/π
28. Oscillation period of the spring pendulum T=2
29. The equation of harmonic oscillations Х=Хmax∙cos
30. Relationship of the wavelength, its speed and period λ= υТ

Molecular Physics and
thermodynamics
31. Amount of substance ν=N/ Na
32. Molar mass
33. Wed. kin. energy of monatomic gas molecules Ek=3/2∙kT
34. Basic equation of the MKT P=nkT=1/3nm0υ2
35. Gay-Lussac law (isobaric process) V/T =const
36. Charles' law (isochoric process) P/T =const
37. Relative humidity φ=P/P0∙100%
38. Int. ideal energy. monatomic gas U=3/2∙M/µ∙RT
39. Gas work A=P∙ΔV
40. Boyle's law - Mariotte (isothermal process) PV=const
41. The amount of heat during heating Q \u003d Cm (T2T1)
g
√π m/k
tω

↓
M=m/v
Optics
86. Law of refraction of light n21=n2/n1= υ 1/ υ 2
87. Refractive index n21=sin α/sin γ
88. Thin lens formula 1/F=1/d + 1/f
89. Optical power of the lens D=1/F
90. max interference: Δd=kλ,
91. min interference: Δd=(2k+1)λ/2
92. Differential lattice d∙sin φ=k λ
The quantum physics
93. Einstein fla for photoelectric effect
hν=Aout+Ek, Ek=Uze
94. Red border of the photoelectric effect νk = Aout/h
95. Momentum of a photon P=mc=h/ λ=E/s
Physics of the atomic nucleus
96. Law of radioactive decay N=N0∙2t/T
97. Binding energy of atomic nuclei
ECB=(Zmp+NmnMn)∙c2
ONE HUNDRED
t=t1/√1υ2/c2
98.
99. ?=?0∙√1υ2/c2
100. υ2=(υ1+υ)/1+ υ1∙υ/c2
101. E \u003d mc2
42. The amount of heat during melting Q \u003d mλ
43. The amount of heat during vaporization Q \u003d Lm
44. The amount of heat during the combustion of fuel Q \u003d qm
45. The equation of state of an ideal gas
PV=m/M∙RT
46. ​​The first law of thermodynamics ΔU=A+Q
47. Efficiency of heat engines = (η Q1 Q2) / Q1
48. Efficiency ideal. engines (Carnot cycle) = (Тη
1 T2)/ T1
Electrostatics and electrodynamics
49. Coulomb's law F=k∙q1∙q2/R2
50. Electric field strength E=F/q
51. The intensity of email. field of a point charge E=k∙q/R2
52. Surface charge density σ = q/S
53. The intensity of email. fields of the infinite plane E=2 kπ σ
54. Dielectric constant ε=E0/E
55. Potential energy of interaction. charges W= k∙q1q2/R
56. Potential φ=W/q
57. Potential of a point charge \u003d φ k∙q / R
58. Voltage U=A/q
59. For a uniform electric field U=E∙d
60. Electric capacity C=q/U
61. Capacitance of a flat capacitor C=S∙ε∙ε0/d
62. The energy of a charged capacitor W \u003d qU / 2 \u003d q² / 2C \u003d CU² / 2
63. Current strength I \u003d q / t
64. Conductor resistance R=ρ∙?/S
65. Ohm's law for the chain section I=U/R
66. Laws of the last. connections I1=I2=I, U1+U2=U, R1+R2=R
67. Laws parallel. conn. U1=U2=U, I1+I2=I, 1/R1+1/R2=1/R
68. Electric current power P=I∙U
69. Joule-Lenz's Law Q=I2Rt
70. Ohm's law for a complete chain I=ε/(R+r)
71. Short circuit current (R=0) I=ε/r
72. Vector of magnetic induction B=Fmax/?∙I
73. Ampere Force Fa=IB?sin α
74. Lorentz force Fl=Bqυsin α
75. Magnetic flux Ф=BSсos α Ф=LI
76. Law of electromagnetic induction Ei=ΔФ/Δt
77. EMF of induction in the conductor conductor Ei=В?υsinα
78. EMF self-induction Esi=L∙ΔI/Δt
79. The energy of the magnetic field of the coil Wm=LI2/2
80. Oscillation period count. contour T=2 ∙√π LC
81. Inductive reactance XL= Lω =2 Lπ ν
82. Capacitance Xc=1/ Cω
83. The current value of the current Id \u003d Imax / √2,
84. The effective value of the voltage Ud \u003d Umax / √2
85. Impedance Z=√(XcXL)2+R2

Definition 1

Physics is a natural science that studies the general and fundamental laws of the structure and evolution of the material world.

Importance of physics in modern world huge. Its new ideas and achievements lead to the development of other sciences and new scientific discoveries, which, in turn, are used in technology and industry. For example, discoveries in the field of thermodynamics made it possible to build a car, and the development of radio electronics led to the emergence of computers.

Despite the incredible amount of accumulated knowledge about the world, human understanding of processes and phenomena is constantly changing and developing, new research leads to new and unresolved issues that require new explanations and theories. In this sense, physics is in a continuous process of development and is still far from being able to explain everything. natural phenomena and processes.

All formulas for $7$ class

Uniform motion speed

All formulas for grade 8

The amount of heat during heating (cooling)

$Q$ - amount of heat [J], $m$ - mass [kg], $t_1$ - initial temperature, $t_2$ - final temperature, $c$ - specific heat

The amount of heat during fuel combustion

$Q$ – amount of heat [J], $m$ – mass [kg], $q$ – specific heat fuel combustion [J / kg]

The amount of heat of fusion (crystallization)

$Q=\lambda \cdot m$

$Q$ – amount of heat [J], $m$ – mass [kg], $\lambda$ – specific heat of fusion [J/kg]

Heat engine efficiency

$efficiency=\frac(A_n\cdot 100%)(Q_1)$

Efficiency - efficiency [%], $A_n$ - useful work [J], $Q_1$ - amount of heat from the heater [J]

Current strength

$I$ - current [A], $q$ - electric charge [C], $t$ - time [s]

electrical voltage

$U$ - voltage [V], $A$ - work [J], $q$ - electric charge [C]

Ohm's law for a circuit section

$I$ - current [A], $U$ - voltage [V], $R$ - resistance [Ohm]

Serial connection of conductors

Parallel connection of conductors

$\frac(1)(R)=\frac(1)(R_1) +\frac(1)(R_2)$

Electric current power

$P$ - power [W], $U$ - voltage [V], $I$ - current [A]

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