Mechanical movement of a body (point) is the change in its position in space relative to other bodies over time.

Types of movements:

A) Uniform rectilinear motion of a material point: Initial conditions

. Initial conditions

G) Harmonic oscillatory motion. An important case of mechanical motion is oscillations, in which the parameters of a point’s motion (coordinates, speed, acceleration) are repeated at certain intervals.

ABOUT scriptures of the movement . There are various ways to describe the movement of bodies. With the coordinate method specifying the position of a body in a Cartesian coordinate system, the movement of a material point is determined by three functions expressing the dependence of coordinates on time:

x= x(t), y=y(t) And z= z(t) .

This dependence of coordinates on time is called the law of motion (or equation of motion).

With the vector method the position of a point in space is determined at any time by the radius vector r= r(t) , drawn from the origin to a point.

There is another way to determine the position of a material point in space for a given trajectory of its movement: using a curvilinear coordinate l(t) .

All three methods of describing the motion of a material point are equivalent; the choice of any of them is determined by considerations of the simplicity of the resulting equations of motion and the clarity of the description.

Under reference system understand a reference body, which is conventionally considered motionless, a coordinate system associated with the reference body, and a clock, also associated with the reference body. In kinematics, the reference system is selected in accordance with the specific conditions of the problem of describing the motion of a body.

2. Trajectory of movement. Distance traveled. Kinematic law of motion.

The line along which a certain point of the body moves is called trajectorymovement this point.

The length of the trajectory section traversed by a point during its movement is called the path traveled .

The change in radius vector over time is called kinematic law :
In this case, the coordinates of the points will be coordinates in time: x= x(t), y= y(t) Andz= z(t).

In curvilinear motion, the path is greater than the displacement modulus, since the length of the arc is always greater than the length of the chord contracting it

The vector drawn from the initial position of the moving point to its position at a given time (increment of the radius vector of the point over the considered period of time) is called moving. The resulting displacement is equal to the vector sum of successive displacements.

During rectilinear movement, the displacement vector coincides with the corresponding section of the trajectory, and the displacement module is equal to the distance traveled.

3. Speed. Average speed. Velocity projections.

Speed - speed of change of coordinates. When a body (material point) moves, we are interested not only in its position in the chosen reference system, but also in the law of motion, i.e., the dependence of the radius vector on time. Let the moment in time corresponds to the radius vector a moving point, and a close moment in time - radius vector . Then in a short period of time
the point will make a small displacement equal to

To characterize the movement of a body, the concept is introduced average speed his movements:
This quantity is a vector quantity, coinciding in direction with the vector
. With unlimited reduction Δt the average speed tends to a limiting value called instantaneous speed :

Velocity projections.

A) Uniform linear motion of a material point:
Initial conditions

B) Uniformly accelerated linear motion of a material point:
. Initial conditions

B) Movement of a body along a circular arc with a constant absolute speed:

MOVEMENT

MOVEMENT

MOVEMENT, movements, cf.

1. only units A state opposite to rest and consisting in the movement of an object or its parts (book scientific). Rotational movement. Forward movement. “Be in a state of movement. - the form of existence of matter." Lenin . “He (Lenin) is unthinkable without movement, he is unthinkable without labor.” Bezymensky .

|| moving an object or its parts in space in a certain direction. Movement of planets. Train movement. “From the balcony of a café, which was created by snobbery and whim, I look at the great movement of thousands (demonstration).” Lenin .

2. Transition, movement from place to place, constant change in the position of something in space. Steam locomotive movement. Movement of enemy troops.

|| Action, operation of some mechanism. Observe the movement of the car.

3. Changing the position of the body or its individual organs in space, gesture. Hand movement. Rhythmic movements. The audience followed all the movements of the speaker. In anger, he made a sudden movement. Graceful movement. With an awkward movement, he broke the glass. Lie motionless.

4. trans. Internal motivation, change in state of mind (book). Soul movement. Movement of pity.

5. only units The action of a particular type of transport, transportation of passengers and goods, driving. Car traffic has opened. Commodity movement. Tram traffic.

|| Riding and walking in different directions (on streets and roads). There is a lot of traffic in the square. Traffic regulation.

6. portable, units only Liveliness. speed and intensity of action (book). There is a lot of movement in the play.

7. portable, units only Social excitement, excitement, fermentation, manifested in some. facts of social life (book). A movement of minds. In 1905, a strong movement against the government emerged among the masses.

8. portable, units only Social activity that sets itself some kind of a specific goal (book). History of the revolutionary movement. Agrarian movement. Professional movement. Collective farm movement. Labor movement. Movement to eradicate illiteracy.

9. only units Transfer from one authority to another (official). Movement of papers. Movement of amounts. Promotion from one position to another, higher one (official pre-revolutionary). Promotion.

10. only units Passage, flow, movement, development in time. Movement of events.

11. only units A quantitative change in something over time. The diagram shows population movement. Price movement.

❖ Freestyle movements (sports) - a special kind of gymnastic exercises without equipment. To come into motion - see come. Set in motion - see drive. Traffic service (railway) - a department of the railway administration in charge of train movement.

Ushakov's Explanatory Dictionary. D.N. Ushakov. 1935-1940.

Synonyms:

Antonyms:

See what “MOVEMENT” is in other dictionaries:

In a broad sense, any change, in a narrow sense, a change in the position of a body in space. D. became a universal principle in the philosophy of Heraclitus (“everything flows”). The possibility of D. was denied by Parmenides and Zeno of Elea. Aristotle divided D. into... ... Philosophical Encyclopedia

MOVEMENT- MOVEMENT (Greek κίνησις, Lat. motus), any change in a thing that involves its transition from one state to another. Types of movement are: qualitative and quantitative change, change in position in space (movement) and... ... Ancient philosophy

See move to set in motion... Dictionary of Russian synonyms and similar expressions. under. ed. N. Abramova, M.: Russian Dictionaries, 1999. movement movement, move, movement, advancement, rearrangement; process, flow, trend, general... ... Synonym dictionary

movement- a structural unit of activity is the result of the work of the psychophysiological apparatus for the implementation of a motor act, through which the interaction of a living being with the external environment occurs. Physiological activity is manifested in movement... ... Great psychological encyclopedia

Movement- Movement ♦ Mouvement Change of place, condition, position or location. Aristotle (Physics, III, 1 and VIII, 7) distinguished four types of motion, which in modern language are better called changes. The main changes correspond to... ... Sponville's Philosophical Dictionary

A group of artists who revived the tradition of constructivism and substantiated the principles of kineticism in Russian culture in the 1960s and 70s. Its leader was L. V. Nusberg, active participants were F. Infante, V. F. Koleichuk and others. The movement sought to bring... ...

In philosophy, the way of existence of matter, in the most general form, change in general, any interaction of objects. Movement acts as a unity of variability and stability, discontinuity and continuity, absolute and relative... Big Encyclopedic Dictionary

In technical analysis, a change in value or price. In English: Movement See also: Market movement charts Classic figures of technical analysis Financial Dictionary Finam... Financial Dictionary

E.T.I. movement Russian art group created by Anatoly Osmolovsky in Moscow in the late 80s. Contents 1 History of creation 2 Participants ... Wikipedia

movement- MOVE, move, move MOVE/MOVE, move/move, move/move, move/move… Dictionary-thesaurus of synonyms of Russian speech

Books

• Movement towards health, youth and longevity. Your own doctor (set of 2 books), Yuri Tangaev, Evgeny Sheremetyev. We present to your attention a set of 2 books: Yuri Tangaev “Movement to Health, Youth and Longevity”, Evgeny Sheremetyev “Your Own Doctor”…

And finally, the most, in my opinion, strange quality of inertial forces. This is the only type of force that does not obey the third law. When a thrown spear turns away from a straight line drawn along the bottom, it does not perceive any opposition, because it does not seem to be connected to anything.

Here it is worth remembering that in the last century, the Austrian physicist Ernst Mach made one very tempting assumption on this matter. This is what he admitted (without any proof): through the property of inertia, any body is connected by some invisible “threads” or “springs” with all, even if immeasurably distant, matter of the Universe. Countless stars are, as Mach said, “not paper lanterns.” Scattered here and there in the boundless world, they somehow collectively act on every star or planet, on every stone, spear, feather - and force them to remain at rest or uniform rectilinear motion relative to inertial reference systems.

Or, if you like, they impart accelerations in non-inertial systems, generating inertial forces.

If this “Mach principle” were true, the forces of inertia would become subject to the third law of mechanics. Like all other forces. The action of the stars on the spear is what would shift it from its straight path in a non-inertial frame of reference. And all the matter of the world would rotate the plane of swing of the Foucault pendulum over the floor of St. Isaac's Cathedral. On the contrary, a spear “tied” to the stars by the Mach principle would exert a counteraction on the stars during acceleration.

So, when throwing a ball, you would push the entire Universe in the opposite direction? Something like that. It’s probably nice to be able to push the whole world!

But I again have to warn my readers against haste. Whether Mach's principle is true or false can be judged only at the very end of this book. Still, I can’t stand it and I’ll tell you now: alas, there has not yet been a place for Mach’s principle in modern science. I hope this confession will not dampen reader interest. I tried to make you most surprised not by inertia, but by heaviness. The miracle of falling cannonballs and bullets, fluff and icicles. It is from this surprise that we must try to escape.

Thus, quite a lot has already been said about the foundations of classical mechanics. The behavior of falling bodies is analyzed, all three laws are explained, and some subtleties are noted.

It's time to say something about specific cases, about her remarkable achievements in explaining nature.

It is not at all necessary to go into space for a non-inertial reference system. No interstellar saucepans or flying saucers required. You can stay on Earth, go to the city garden and ride on the “wheel of laughter” - a horizontal slippery rotating disk. You will feel for yourself the non-inertiality of the reference system associated with the disk - you will very quickly find yourself thrown away from the center of rotation.

You can go to Leningrad and visit St. Isaac's Cathedral. It clearly shows that the reference system associated with the Earth is also non-inertial.

All other frames of reference in physics are called non-inertial.

The reader has already absorbed so much wisdom into his head that I will now ask him the deepest philosophical and physical question: what is movement?

Really, what? We always say “moves,” but do we understand what this word means?

From Pushkin:

There is no movement,” said the bearded sage.

The other fell silent and began to walk in front of him.

In other (and longer) terms, the sage began to change his spatial position in relation to his “bearded” colleague over time. This said it all without words. This determined essence mechanical motion - exactly as it is understood in physics.

Remember: movement is a change over time in the position of a body in some frame of reference. The last words are absolutely required. It is very important to clearly understand: without frame of reference space and time of movement does not exist.

For the “bearded sage,” the reference system was apparently the bench and the ground on which he was sitting, plus the beats of his heart, which played the role of a clock. In this system, the second sage changed his position. Which means it was moving. The physicist does not put anything else into the concept of mechanical motion.

A reference system is a certain material basis for measuring distances and durations. Let's say, a set of fastened rulers, goniometer tools, watches. Even if they do not exist, they can always be imagined, imagined when it comes to movement. This is what we did before, talking about and. We will continue to do so - and often with greater certainty and specificity.

What has been said now provides food for complex and deep thoughts. We will deal with them later, in the following parts of this book. But the most significant features of reference systems, their connection with the laws of motion should be noted immediately.

In fulfillment of the third law there will be recoil, the very thing that pushes the butt of a fired gun into the hunter’s shoulder and propels the space rocket. When the severed bow of the boat rushes forward, its stern will bounce back. Ejecting a powerful stream of hot gases, the jet engine lifts and accelerates the spacecraft.

And not only space.

"TU-104" is an atmospheric jet aircraft. Its engine is similar to a rocket engine. But this is interesting. Not only he, but also all other aircraft, including propeller-driven ones, are also, strictly speaking, jets. And cars, locomotives, steamships, bicycles, chaises, stagecoaches, and pedestrians are again reactive. Such, in essence, are almost all the movements around us. All who are subject to the third law and owe their existence to it. The rocket differs only in that it itself prepares the reactive “working fluid” - hot gases, which it throws away and the reaction of which moves it in the opposite direction. And for a propeller-driven airplane, car, or steamship, the jet “working fluid” is already ready - air, road, water. By “throwing” them back, the crew moves forward. The third law applies.

I walk on the planet because I push it back with my feet. The planet, however, is in no hurry to accelerate in the opposite direction. Because it has enormous mass. If in my place there was a squirrel, and in the place of the planet there was a wheel, the reactivity of the movement would become very noticeable - the mass of the wheel is relatively small, and therefore its inertia.

Movement- any change in general, from the spatial movement of objects to human thinking. Movement is an attribute of matter, an integral property of any material object. There is no matter without movement and vice versa. Movement is an abstraction, the ability to change its parameters, abstracted by our consciousness from real material objects. Therefore, movement in its “pure form” exists only in thinking, but in reality only moving material objects exist. There cannot be an absolutely motionless material object. Peace- opposite to movement (lack of movement). Any moving object is identified. time retains its qualitative certainty, the stability of the internal structure, that is, some constancy, immutability. This is an indispensable condition for the existence of any thing. That. movement and rest are dialectically contradictory properties of a material object.
Development- irreversible qualitative change. It can be progressive - occurring with an increase in the complexity and orderliness of the object, and regressive - degradation of the object, its disintegration, death. Engels identified 5 main forms of movement:
1. Mechanical
2. Physical
3. Chemical
4. Biological
5. Social
All these forms of movement are interconnected and simpler ones are included in more complex ones, forming a qualitatively different form of movement. Each of these forms includes an infinite number of types of movement. Even, according to Engels, the simplest mechanical motion includes such types of motion as uniformly rectilinear, uniformly accelerated (slow), curvilinear, chaotic, etc.
The most complex form of movement is social, since the material carrier is the most complex type of matter - social. This form of movement also includes changes that occur in the individual’s body. Thus, the human heart is a mechanical engine that ensures the movement of blood in the vessels. But this is not a purely mechanical engine. Its activity is regulated by the mechanisms of human higher nervous activity. And the vital activity of the body is a condition for human participation in work and in public life. This includes changes in social groups, strata, classes, ethnic changes, demographic processes, the development of productive forces and production relations and other changes determined by the laws of motion at the social level of matter.
It should be emphasized that various forms of motion are capable of transforming into each other in accordance with the laws of conservation of matter and motion. This is a manifestation of the property of indestructibility and non-creation of matter and motion. The measure of motion of matter is energy, the measure of rest and inertia is mass.

38). The concept of space and time in philosophy. Modern scientific and philosophical ideas about space and time.

Space is a form of coordination of coexisting objects, states of matter. It lies in the fact that objects are located outside each other (next to each other, on the side, below, above, inside, behind, in front, etc.) and are in certain quantitative relationships. The order of coexistence of these objects and their states forms the structure of space.
Phenomena are characterized by the duration of their existence and the sequence of development stages. Processes occur either simultaneously, or one earlier or later than the other; such, for example, are the relationships between day and night, winter and spring, summer and autumn. All this means that bodies exist and move in time. Time is a form of coordination of changing objects and their states. It lies in the fact that each state represents a sequential link in the process and is in certain quantitative relationships with other states. The order in which these objects and states change forms the structure of time.
Space and time- these are universal forms of existence, coordination of objects. The universality of these forms of existence lies in the fact that they are the forms of existence of all objects and processes that were, are and will be in the infinite world. Space and time have their own characteristics. Space has three dimensions: length, width and height, and time has only one - the direction from the past through the present to the future. It is inevitable, unique and irreversible.
In the history of philosophy, there have been various concepts of space and time. They can be divided into two large classes: substantial and relational concepts. The substantial concept views space and time as special entities that exist on their own, regardless of material objects. They are like an arena in which objects are located and processes unfold. Just as an arena can exist without certain objects being placed on it, actors moving, or some kind of performance being played out, so space and time can exist independently of material objects and processes. In contrast to the substantial approach, a relational concept of space and time developed in the history of philosophy. One of its most prominent representatives was G. W. Leibniz. He insisted that space and time are special relations between objects and processes and do not exist outside them.
The achievements of modern science indicate the preference of a relational approach to understanding space and time. In this regard, first of all, it is necessary to highlight the achievements of physics of the 20th century. The creation of the theory of relativity was a significant step in understanding the nature of space and time, which allows us to deepen, clarify, and concretize philosophical ideas about space and time.
The special theory of relativity, the construction of which was completed by A. Einstein in 1905, proved that in the real physical world, spatial and time intervals change when moving from one reference system to another.
It turned out that only when the speeds of movement are small in relation to the speed of light, we can approximately assume that the sizes of bodies and the passage of time remain the same, but when we are talking about movements with speeds close to the speed of light, then a change in spatial and time intervals becomes noticeable. With an increase in the relative speed of movement of the reference system, spatial intervals are reduced and time intervals are stretched.
The theory of relativity has revealed another significant aspect of the space-time relations of the material world. She revealed a deep connection between space and time, showing that in nature there is a single space-time, and separately space and time act as its unique projections, into which it is split in different ways depending on the nature of the movement of bodies.
Thus, philosophical conclusions from the special theory of relativity testify in favor of a relational consideration of space and time: although space and time are objective, their properties depend on the nature of the movement of matter and are associated with moving matter.

39). The concept of dialectics in the history of philosophy. Dialectics as a doctrine of universal connection and development.

Dialectics is theory and universal method of cognition and transformation of reality. Dialectics in cognition does not replace the special methods of specific sciences, but is their common basis, acts as a way of reproducing in thinking the most general laws, properties and relations of objective reality. The elements of dialectics are its principles, categories and laws. Elements of dialectics can be inherent in various, including opposing, philosophical directions: materialism and idealism.
The opposite of the dialectical method is metaphysics(remember that this term is also used as a synonym for ontology or the concept of philosophy in general). The metaphysical method is characterized by a tendency to construct an unambiguous and static picture of the world, a one-sided interpretation of phenomena, and a reduction (reduction) of the complex to the simple.
One of the basic principles of dialectics is the principle of universal connection. Connection- this is a state of interdependence of phenomena and processes, the dependence of some phenomena and processes on others in some respect. Everything in the world is interconnected. Connections can be significant and insignificant, direct and indirect, internal and external, direct and reverse, etc.
The universal connection of phenomena in our time is recognized in almost all philosophical systems. The “new” metaphysics also recognizes the existence of a universal connection, but is characterized by a subjectivist snatching of individual aspects and properties of an object and their arbitrary mechanical connection. This is a simplified approach, a manifestation of eclecticism, that is, an unsystematic combination of various information and knowledge.
The most important attribute (inherent property) of existence is movement, which includes all processes occurring in the world. The philosophical understanding of motion covers any interaction of any objects. Movement- this is a change in general. Movement is absolute, universal, while rest is relative. Thus, a body at rest on the surface of the Earth is in motion together with the Earth around the Sun, and together with the Solar system, a body at rest on the Earth moves around the center of the Galaxy, etc.
A special case of motion is development. In the course of development, a fundamentally new emergence takes place, a transition of things and phenomena to a different qualitative state. In the process of the formation of the new, the unity of the existing and the non-existent, being and non-being is uniquely reflected. The new arises on the basis of the old as the prerequisites and conditions for the transition from the old to the new take shape.
Movement can be carried out both along ascending and descending branches. In the first case it will be progressive development, and in the second - regressive.
Let us recall that matter refers to the entire objective reality that is given to a person in his sensations. Regular and diverse transitions from old quality to new lead to the fact that there are qualitatively different types of objects and processes in the world. The main types of movement and interaction of objects existing in the world are called forms of matter movement. According to modern science, there are three main groups of movement forms matter: in inorganic nature, in living nature, in society. Taking into account the accepted classification of sciences, physical, chemical, biological and social forms of movement are usually considered.
The interconnection of all existing forms of movement testifies to the material unity of the world. As already noted, this relationship is characterized by a combination and complex interaction of progressive and regressive trends. The progressive trend of change involves an increase in the degree of organization of systems. In its most general form, it manifests itself in a consistent transition in the process of evolution of the Universe from physical to chemical, biological and social forms of movement. This sequence indicates a certain direction of changes in the objective world, confirming the applicability of the principles of development to the world we observe as a whole.
PHYSICAL CHANGES are inherent in any objects of nature and, to a first approximation, can be specified through known types of interaction: electromagnetic, gravitational, strong (nuclear) and weak. The sources of interaction are, respectively, electric charge, mass, light charge, weak charge. Electromagnetic and gravitational interactions have an infinite radius, strong and weak interactions appear only in the microcosm.
Chemical form movement occurs at a certain stage of the evolution of the Universe, when the genesis of chemical elements occurs and various atomic-molecular structures arise. The process of synthesis of chemical elements in nature continues in our era. Thus, red giant stars and so-called supernovae are real “factories for the production of elements.”
The complication of chemical compounds and the emergence of highly organized supramolecular structures (chemical evolution) ensured a natural transition to a higher form of matter motion associated with life - b i o l o g i c h e s. Life is realized in individual organisms and in their aggregates (populations, species, etc.). According to genetics, environmental influences (for example, radioactive or ultraviolet radiation) lead to mutations and may be accompanied by the emergence of qualitatively new organisms. Thanks to natural selection, the organisms most adapted to environmental conditions survive and give rise to new biological species.
At the pinnacle of biological evolution are the great apes. The closest ancestors of humans, Australopithecus, several million years ago switched to a terrestrial lifestyle and the use of natural objects as tools. The systematic use of tools was accompanied by the beginnings of social production, and later labor activity created the preconditions for the emergence of consciousness and speech. The process of formation of man and society led to the emergence of a social form of the movement of matter.
Evolutionary changes in society, i.e., an increase or decrease in what exists, prepare revolutionary processes - the emergence of a qualitatively new one. Evolutionary and revolutionary processes are dialectically interconnected. New things cannot come out of nothing. The new is the result of development on the basis of the old, existing, although it is not a repetition of it in the main and fundamental way. There is a dialectical negation here, which will be discussed below.
The higher forms of movement include the lower forms in a transformed form. At the same time, the highest forms of movement are not reducible to the lowest. Thus, the phenomena of life cannot be fully explained and predicted based on the laws describing physical and chemical processes. In the same way, the social cannot be reduced to the natural. For example, morality, love, patriotism, etc. cannot be explained based on anatomy, physiology, genotype or any other biological characteristics of a person.

Mechanical movement is a change in the position of a body in space relative to other bodies.

For example, a car is moving along the road. There are people in the car. People move along with the car along the road. That is, people move in space relative to the road. But relative to the car itself, people do not move. This shows up. Next we will briefly consider main types of mechanical movement.

Forward movement- this is the movement of a body in which all its points move equally.

For example, the same car makes forward motion along the road. More precisely, only the body of the car performs translational motion, while its wheels perform rotational motion.

Rotational movement is the movement of a body around a certain axis. With such a movement, all points of the body move in circles, the center of which is this axis.

The wheels we mentioned perform rotational motion around their axes, and at the same time, the wheels perform translational motion along with the car body. That is, the wheel makes a rotational movement relative to the axis, and a translational movement relative to the road.

Oscillatory motion- This is a periodic movement that occurs alternately in two opposite directions.

For example, a pendulum in a clock performs an oscillatory motion.

Translational and rotational movements are the simplest types of mechanical movement.

Relativity of mechanical motion

All bodies in the Universe move, so there are no bodies that are at absolute rest. For the same reason, it is possible to determine whether a body is moving or not only relative to some other body.

For example, a car is moving along the road. The road is located on planet Earth. The road is still. Therefore, it is possible to measure the speed of a car relative to a stationary road. But the road is stationary relative to the Earth. However, the Earth itself revolves around the Sun. Consequently, the road along with the car also revolves around the Sun. Consequently, the car makes not only translational motion, but also rotational motion (relative to the Sun). But relative to the Earth, the car makes only translational motion. This shows relativity of mechanical motion.

Relativity of mechanical motion– this is the dependence of the trajectory of the body, the distance traveled, movement and speed on the choice reference systems.

Material point

In many cases, the size of a body can be neglected, since the dimensions of this body are small compared to the distance that this body moves, or compared to the distance between this body and other bodies. To simplify calculations, such a body can conventionally be considered a material point that has the mass of this body.

Material point is a body whose dimensions can be neglected under given conditions.

The car we have mentioned many times can be taken as a material point relative to the Earth. But if a person moves inside this car, then it is no longer possible to neglect the size of the car.

As a rule, when solving problems in physics, we consider the movement of a body as motion of a material point, and operate with such concepts as the speed of a material point, the acceleration of a material point, the momentum of a material point, the inertia of a material point, etc.

Frame of reference

A material point moves relative to other bodies. The body in relation to which this mechanical movement is considered is called the body of reference. Reference body are chosen arbitrarily depending on the tasks to be solved.

Associated with the reference body coordinate system, which is the reference point (origin). The coordinate system has 1, 2 or 3 axes depending on the driving conditions. The position of a point on a line (1 axis), plane (2 axes) or in space (3 axes) is determined by one, two or three coordinates, respectively. To determine the position of the body in space at any moment in time, it is also necessary to set the beginning of the time count.

Frame of reference is a coordinate system, a reference body with which the coordinate system is associated, and a device for measuring time. The movement of the body is considered relative to the reference system. The same body relative to different reference bodies in different coordinate systems can have completely different coordinates.

Trajectory of movement also depends on the choice of reference system.

Types of reference systems can be different, for example, a fixed reference system, a moving reference system, an inertial reference system, a non-inertial reference system.