Involuntary and voluntary movements according to Sechenov. Movement and development

Reflexes of the brain

In this work, I.M. Sechenov asserts his thesis that all external manifestations of brain activity can be reduced to muscle movement. (Whether a child laughs at the sight of a toy, whether Garibaldi smiles when he is persecuted for excessive love for his homeland, whether a girl trembles at the first thought of love, whether Newton creates world laws and writes them on paper - everywhere the final fact is muscle movement).

This is the work of I.M. Sechenov is an introductory part of his so-called theory. It is in it that he divides by origin all muscle movements into two groups - involuntary and voluntary, it is to them that he will devote his subsequent chapters, where he will give them a more complete and accurate analysis.

Involuntary movements

Three types of involuntary movements:

1) Reflexes (in the narrow sense) on decapitated animals, movements in a person during sleep and under conditions when his brain is said to be inactive

2) Involuntary movements where the end of the act is weakened against the beginning of its more or less strongly delayed involuntary movements

3) Involuntary movements with a reinforced end - fright, elementary sensual pleasures. - Cases where the intervention of a mental moment in a reflex does not change the nature of the latter. - Somnambulism, intoxication, feverish delirium, etc.

The main theoretical part on the topic of involuntary movements is proved by I.M. Sechenov through examples of experiments on a headless frog.

I. M. Sechenov describes involuntary movements as the simplest mechanism: sensory nerve threads stretch from the skin to the spinal cord, and nerves of movement go out of the spinal cord to the muscles; in the spinal cord itself, both kinds of nerves are connected with each other through the mediation of the so-called nerve cells. Thanks to this connection, reflected movements- excitation of the sensory nerve is reflected in the moving one.

But the brain can also act like a machine. THEM. Sechenov cites as an example a nervous lady who shudders when her fist strikes the table at a certain force of impact. Over time, she ceases to shudder. With an increase in the force of the blow, it shudders again, and when it is repeated, it stops. This phenomenon manifests the determinism of behavior, which I.M. Sechenov formulates into law: if the excitation of the sensory nerve is stronger than it has ever been able to withstand, then under all possible conditions it causes fatal reflections, i.e. involuntary movements.

But at the same time, if a person is prepared for external influence, then regardless of the final effect, opposition to this influence will always be born in him. This is due to the functioning of the brain.

In addition, the brain regulates the relationship between the strength of the stimulus and its effect.

With the suddenness of the action of the stimulus, a person has a fright. The highest degree of fright is fainting and petrification. These phenomena are related. Fainting occurs due to reflection from the sensory nerve to the wandering one. Excited, he weakens or even stops the beating of the heart. Fossilization is usually expressed by an increased and prolonged contraction of the muscles of the face and some of the other muscles of the body.

Sechenov reflex brain

Then Sechenov smoothly proceeds to reveal the combination of the activity of individual reflective elements into a complex reflected action.

He logically deduces the so-called necessity : without intercellular communication it would be impossible to explain the origin of even the most elementary reflex.

But are all the reflective elements of the body evenly combined with each other?

Answer: the whole body of the animal can be divided into 4 main reflective groups: the head - the skin and muscles of the head with their reflective connection, the trunk - the skin and muscles of the body with their nervous connection, the group of the upper limbs and the same group of the lower. Each group is separate from the others and can act independently, but at the same time it is connected with all the others.

The mechanism for grouping reflective elements is:

1. In general, in the combination of nerve cells with each other by processes

2. In connection with some reflective elements, from their total amount in the body, with central mechanisms isolated from others in the medulla oblongata (and maybe in other parts of the brain).

The main characters of involuntary movements:

1. Movement occurs quickly after sensory stimulation.

2. Both more or less correspond to each other.

3. Involuntary movements are always expedient. They are aimed at survival (in some of the cases, expediency is brought to such an extent that the movement ceases to seem automatic to the observer and begins to take on the character of a reasonable one).

Consider such complex human behavior as a drunken state and the behavior of a sleepwalker. When analyzing these examples, we get:

1. Involuntary movements can be combined with movements arising from certain mental representations.

2. Involuntary movements can represent a range of acts

3. There are cases of involuntary movement where the presence of sensual excitation, the beginning of every reflex, although understood, cannot be clearly defined.

Thus, in a lunatic tightrope walk, an involuntary movement can be combined with walking, an act arising from some mental representation, with a non-instinctive movement.

All movements according to the mechanism of their origin are always involuntary if they occur without the participation of the reasoning ability.

This ends the scope of involuntary movements.

Arbitrary movements

The main properties of arbitrary movements of I.M. Sechenov says:

1. The basis of the movement is not tangible sensual excitement

2. Movements are determined only by the highest mental motives, the most abstract ideas, for example, the thought of the welfare of the human race, love for the motherland, etc.

3. Fluctuations of external activity down to perfect dispassion obeys the will; intensification of movements is possible only to a certain extent

4. The time of the onset of an external act, if its mental motive is not complicated by passion, lies in the will of a person (and this complication stems mainly from self-consciousness)

5. The duration of the external movement is again, to a certain extent, subject to the will (by self-consciousness); it is limited by greater or lesser fatigue of the nerves and muscles. The highest passion of the psychic motive always pushes external activity to the limits that lie in the organization of muscles and nerves.

6. Highly voluntary movements often go against the sense of self-preservation. They are expedient only from the point of view of the mental motive that causes them.

7. The grouping of individual voluntary movements into rows is controlled by the will (by self-consciousness). The condition here again is the absence of passion in the psychic motive.

8. Voluntary movement is always conscious.

But is there really no sensual excitation at the basis of voluntary movement? If there is, then why is it masked in the typical form of this phenomenon?

Example: a person is born into the world with a very small amount of instinctive movements and sensations. Including visual sensations in a newborn are weak. The child usually holds objects of bright colors in front of his eyes. His eye, wandering in different directions, receives light sensations of varying strength, but most of all when the visual axis has fallen on an object. The child's brain is so arranged that the brighter the light, the more he likes it. It is clear that under this condition the child, without any reasoning, i.e. involuntarily, will strive to keep the eye in the position in which the sensation is more pleasant. History repeats itself not once, not twice, but a thousand times, and the child learns to look. Muscular movement, which plays the main role here, is an act always involuntary, developing in a given direction under the influence of habit.

Thus , through a completely involuntary study of successive reflexes in all spheres of the child's senses, there is a darkness of more or less complete ideas about objects - elementary concrete knowledge. The latter occupy the same place in the whole reflex as the sensations of fear in involuntary movement; correspond to the activity of the central element of the reflective apparatus. The activity of the newborn also plays a huge role here.

Now about the new entity: a person, as you know, has the ability think in images, words, and other sensations, which have no direct connection with what at that time acts on his senses. In his mind, therefore, images and sounds are drawn without the participation of the corresponding external real images and sounds. But since he had seen and heard all these images and sounds before in reality, since the ability to think with them, without the corresponding external substrates, is called sensation-reproducing ability.

It turns out that sound, image and every sensation are stored in the nervous apparatus in a latent state between the actual sensation and the moment of its reproduction. It's about memory. Without it, every real sensation would leave no trace of itself, and for the millionth time it would be perceived as the first.

The trace of sensation remains for a long time, and after the disappearance of the beginning of the clear subjective sensation that accompanies it, it is completely natural. The feeling is stored in a latent form.

If the preservation of sensation in a latent form during the night is understandable, then its preservation for years becomes understandable. So, when remembering a person who once met, a lot of heterogeneous discrete sensations are obtained: movement and facial features, posture, gait and manner of speaking, the sound of the voice, the subject of conversation - everything remains in the memory more or less for a long time, depending on the strength of the impression, but, finally, everything traces begin to gradually weaken. Suddenly, another person comes across, between discrete sensations from which there is one very similar to the corresponding one from the first. The latter revives, refreshes; as if again standing in front of the old feeling. If such conditions are repeated from time to time, the trace does not disappear.

So, from the frequency of repetition of a real sensation or reflex, the sensation becomes clearer, and through this and the very preservation of it by the nervous apparatus in a latent state becomes stronger. The hidden trace persists longer and longer, the sensation is more difficult to forget.

Visual and purely tactile memory can be called spatial.

Auditory and muscular - the memory of time.

Let us show how associated sensations merge into a whole.

Conditions: association - a successive series of reflexes, in which the end of each previous one merges with the beginning of the next one in time and the strengthening of this association is the frequency of repetitions of the association in the same direction. When she formed the slightest external allusion to a part of it entails the reproduction of the whole association.

Between the actual impression with its consequences and the memory of this impression, on the part of the process, in essence, there is not the slightest difference. This is the same mental reflex with the same mental content, only with a difference in stimuli. I see a person because his image is really drawn on my retina, and I remember because the image of the door near which he was standing fell on my eye.

Sechenov concludes: without exception, all mental acts that are not complicated by a passionate element develop through a reflex. Consequently, all the conscious movements arising from these acts, the movements usually called voluntary, are in the strict sense reflected.

And along with the fact that a person, by means of frequently repeated associated reflexes, learns to group his movements, he acquires (by the same way of reflexes) the ability to delay them. From this follows that huge series of phenomena where mental activity remains, as they say, without external expression, in the form of thought, intention, desire ...

What then is contemplation? Sechenov answers as follows: thought is the first two-thirds of the mental reflex.

Another property of thought is that it is endowed to a high degree with the character of subjectivity.

But the fact that thought is the cause of an action is a delusion, because the original cause of any action always lies in external sensual excitement, because without it no thought is possible.

One of the special acts of conscious life is passion. Sechenov considered her enhanced reflex.

Passion breeds an unsatisfied need. Most often, this is a very bright thing that attracts us and, of course, rare. Since everything, even insignificantly new, interests us - and constantly encountered, even exquisite, bothers and dulls. Also in moral ideals - the boy, seeing in the picture a knight in bright clothes, mastered the passion of the ideal. He began to imitate him outwardly. Then he learned about the moral values ​​of a knight and began to imitate them first of all, believing that it is in them that the main essence of a knight lies. Then, having matured, the boy forgot about the knight, and past moral judgments turned into a stereotypical habit and became an integral part of the personality.

Love for a woman is manifested in a similar way. A boy falls in love with a girl who is not always of his circle - since those women who surround him since childhood evoke other associations in him. He falls in love with a vague image that gives only the best qualities, and then, having met, in his opinion, a similar girl, he transfers his ideal of a woman to her and loves this ideal in her, and not her real, in fact. Then he discovers many new things in it, the flame of passion flares up, but after two or three years the passion fades away (not love, but passion). Since, according to the laws of any reflex, with the constant manifestation of the stimulus, its effect fades due to fatigue of the receptors. But if the ideal of a woman was close to the ideal, then love continues in the form of friendship. And the manifestation of such passion is rarely possible again, because the ideal is found and this girl has already become an integral part of his ideal girl. The re-emergence of passion speaks of some kind of dissatisfaction.

Sechenov ends the chapter with the argument that without external sensory stimulation, psychic activity and its expression, muscular movement, are possible even for a moment. After all, if you take away the feeling nerves from a person, deprive him of hearing and sight, nothing will affect his peace, and he will sleep forever - until death.



It is not easy to find an adult who has never heard the catchphrase "Movement is life" in his life.


There is another formulation of this statement, which sounds somewhat different: "Life is movement." The authorship of this aphorism is usually attributed to Aristotle, the ancient Greek scientist and thinker, who is considered the founder of all "Western" philosophy and science.

Today it is difficult to say with complete certainty whether the great ancient Greek philosopher really ever uttered such a phrase, and how exactly it sounded in those distant times, but, looking at things with an open mind, it should be recognized that the above definition of movement is, although sonorous, but quite vague and metaphorical. Let's try to figure out what constitutes a movement from a scientific point of view.

The concept of motion in physics

Physics gives the concept "movement" quite specific and unambiguous definition. The branch of physics that studies the motion of material bodies and the interaction between them is called mechanics.

The section of mechanics that studies and describes the properties of motion without taking into account its specific causes is called kinematics. From the point of view of mechanics and kinematics, movement is a change in the position of a physical body relative to other physical bodies that occurs over time.

What is Brownian motion?

The tasks of physics include the observation and study of any manifestations of motion that occur or could occur in nature.

One of the types of motion is the so-called Brownian motion, known to most readers of this article from a school physics course. For those who, for some reason, were not present during the study of this topic or had time to thoroughly forget it, let us explain: Brownian motion is the random movement of the smallest particles of matter.


Brownian motion occurs wherever there is any matter whose temperature exceeds absolute zero. Absolute zero is the temperature at which the Brownian motion of particles of matter should stop. According to the Celsius scale, which we are used to using in everyday life to determine the temperature of air and water, the temperature of absolute zero is 273.15 ° C with a minus sign.

Scientists have not yet been able to create conditions that cause such a state of matter, moreover, there is an opinion that absolute zero is a purely theoretical assumption, but in practice it is unattainable, since it is impossible to completely stop the oscillations of matter particles.

Movement in terms of biology

Since biology is closely related to physics and in a broad sense is completely inseparable from it, in this article we will consider the movement also from the point of view of biology. In biology, movement is considered as one of the manifestations of the vital activity of an organism. From this point of view, movement is the result of the interaction of forces external to a single organism with the internal forces of the organism itself. In other words, external stimuli cause a certain reaction of the body, which manifests itself in movement.

It should be noted that although the formulations of the concept of "motion", adopted in physics and biology, are somewhat different from each other, in their essence they do not enter into the slightest contradiction, being simply different definitions of the same scientific concept.


Thus, we are convinced that the catchphrase, which was discussed at the beginning of this article, is quite consistent with the definition of motion from the point of view of physics, so we can only repeat the common truth once again: motion is life, and life is motion .

• MOVEMENT, -I, cf.

  1. Changing the position of an object or its parts, moving; a state opposite to immobility, rest. Rotational movement. oscillatory movement. rhythmic movement. Get in motion. □ [The aircraft] obediently responded to every movement of the control levers. B. Polevoy, The Tale of a Real Man. || Action, work mechanism. The noisy waves of it [Terek] set in motion the wheels of low Ossetian mills. Pushkin, Journey to Arzrum. The complex movement of fifteen machines was controlled by only one person. Kuprin, Moloch. [Petya], without looking up, followed the movement of the huge scissors, cutting thick zinc like paper. Kataev, A lonely sail turns white.

  2. Philos. The mode of existence of matter, its universal inalienable property; continuous process of change and development of the material world. The metaphysical, i.e. anti-dialectical, materialist can accept the existence of matter (at least temporarily, until the “first push”, etc.) without movement. The dialectical materialist not only considers motion to be an inseparable property of matter, but also rejects a simplified view of motion, etc. Lenin, Materialism and Empirio-Criticism.

  3. Movement in space in some direction; movement. After the battle of Borodino, the occupation of Moscow by the enemy and its burning, historians recognize the movement of the Russian army from the Ryazan to the Kaluga road and to the Tarutinsky camp as the most important episode of the war of 1812. L. Tolstoy, War and Peace. The horse rearranged its legs, the sledgehammer lurched to the right and to the left, but there was no feeling of riding, no movement. Fedin, Cities and Years. The formulas proposed by him [Tatarinov] make it possible to calculate the speed and direction of ice movement in any region of the Arctic Ocean. Kaverin, Two captains. || The action of a particular mode of transport. Tram traffic. Passenger traffic. □ Passenger trains were already going from Kharkov to Moscow. The movement was not yet regular, it was just beginning. Inber, A place in the sun. || Riding and walking in different directions (on streets, roads, etc.). Traffic rules. □ There was already heavy traffic in the corridors of the court when Nekhlyudov entered it. Watchmen ran back and forth with errands and papers. The bailiff, lawyers and judges passed here and there. L. Tolstoy, Resurrection. There were people on the street. There were so many that traffic stopped. Neither the tram nor the cars could break through the living wall. Tikhonov, Stories about Pakistan. || The transition from one instance to another, from one position to another, promotion, move. The movement of amounts. Paper movement. □ [Prince Andrei] had to the highest degree that practical tenacity that Pierre lacked, which, without scope and effort on his part, gave movement to the cause. L. Tolstoy, War and Peace. Participation in this business was drawn to him as the beginning of a very significant, even, perhaps, decisive movement in his career. Fedin, First joys.

  4. Change in the position of the body or its parts; body movement, gesture. Peter comes out. His eyes Shine. His face is terrible. The movements are fast. Pushkin, Poltava. By the movement of his hand --- Katya realized that the young man was reading poetry. A. N. Tolstoy, Gloomy morning. Admiral Milne rises, and Mitford repeats this movement. Lavrenev, Strategic mistake. Her short hair hung down over her eyes, which she tossed aside with a quick movement of her head. Krymov, Tanker "Derbent".

  5. what or which. Inner urge, emotional experience. He was a large man, with a sharpened face --- and, as it were, frozen features, which did not easily betray spiritual movements. Korolenko, Frost. You will have to suppress the natural movements of the heart, frown when you are happy, laugh when you are in pain. A. Goncharov, Our correspondent.

  6. trans. Public activity pursuing certain goals. Peace movement. National liberation movement. revolutionary movement. □ I tried to get acquainted with the partisan movement in the Crimea as much as possible. I. A. Kozlov, In the Crimean Underground.

  7. Quantitative or qualitative change; growth, development. Population movement. □ - Here [in animal husbandry] a decent advance is planned for each collective farm. Babaevsky, Cavalier of the Golden Star.

  8. The development of action in a literary work, its tension, liveliness. The author's story is sometimes clothed in the lightness of a romantic narrative, and sometimes comes to a dramatic movement. Belinsky, Wanderer on land and seas<Е. Г. Ковалевского>.

  free movement cm. freestyle.
  Sweeping water movements cm. to look forward to.

Source (printed version): Dictionary of the Russian language: In 4 volumes / RAS, Institute of Linguistics. research; Ed. A. P. Evgenieva. - 4th ed., erased. - M.: Rus. lang.; Polygraphic resources, 1999; (electronic version):

mechanical movement

Mechanical movement body is called the change in its position in space relative to other bodies over time. In this case, the bodies interact according to the laws of mechanics.

The section of mechanics that describes the geometric properties of motion without taking into account the causes that cause it is called kinematics.

More generally movement is called the change in the state of a physical system over time. For example, we can talk about the motion of a wave in a medium.

Types of mechanical movement

Mechanical motion can be considered for different mechanical objects:

• Movement of a material point is completely determined by the change in its coordinates in time (for example, two on a plane). The study of this is the kinematics of the point. In particular, important characteristics of motion are the trajectory of a material point, displacement, speed and acceleration.
  • rectilinear the movement of a point (when it is always on a straight line, the speed is parallel to that straight line)
  • Curvilinear motion�- movement of a point along a trajectory that is not a straight line, with arbitrary acceleration and arbitrary speed at any time (for example, movement in a circle).
• Rigid body motion consists of the movement of any of its points (for example, the center of mass) and rotational movement around this point. Studied by the kinematics of a rigid body.
  • If there is no rotation, then the movement is called progressive and is completely determined by the movement of the selected point. The movement is not necessarily linear.
  • For description rotary motion�- movements of the body relative to the selected point, for example, fixed at a point,�- use Euler angles. Their number in the case of three-dimensional space is three.
  • Also, for a solid body, flat motion�- movement, in which the trajectories of all points lie in parallel planes, while it is completely determined by one of the sections of the body, and the section of the body �- by the position of any two points.
• Continuum motion. It is assumed here that the motion of individual particles of the medium is quite independent of each other (usually limited only by the conditions of continuity of the velocity fields), so the number of defining coordinates is infinite (functions become unknown).

Motion geometry

Relativity of motion

Relativity - the dependence of the mechanical motion of the body on the frame of reference. Without specifying the reference system, it makes no sense to talk about motion.

The concept of mechanics. Mechanics is a part of physics in which they study the movement of bodies, the interaction of bodies, or the movement of bodies under some kind of interaction.

The main task of mechanics is the determination of the location of the body at any given time.

Sections of mechanics: kinematics and dynamics. Kinematics is a branch of mechanics that studies the geometric properties of motions without taking into account their masses and the forces acting on them. Dynamics is a branch of mechanics that studies the motion of bodies under the action of forces applied to them.

Movement. Movement characteristics. Motion is a change in the position of a body in space over time relative to other bodies. Characteristics of movement: distance traveled, movement, speed, acceleration.

mechanical movement – this is a change in the position of a body (or its parts) in space relative to other bodies over time.

translational movement

Uniform body movement. Demonstrated by video demonstration with explanations.

Uneven mechanical movement A motion in which a body makes unequal displacements in equal intervals of time.

Relativity of mechanical motion. Demonstrated by video demonstration with explanations.

Reference point and frame of reference in mechanical motion. The body relative to which the movement is considered is called the reference point. The reference system in mechanical movement is the reference point and the coordinate system and the clock.

Reference system. Characteristics of mechanical movement. The reference system is demonstrated by a video demonstration with explanations. Mechanical movement has characteristics: Trajectory; Path; Speed; Time.

Rectilinear trajectory is the line along which the body moves.

Curvilinear motion. Demonstrated by video demonstration with explanations.

Path and the concept of a scalar quantity. Demonstrated by video demonstration with explanations.

Physical formulas and units of measurement of mechanical motion characteristics:

Value designation	Quantity units	Formula for determining the value
Path-s	m, km	S= vt
Time- t	s, hour	T = s/v
Speed ​​-v	m/s, km/h	V = s/ t

P concept of acceleration. Revealed by a video demonstration, with explanations.

Formula for determining the amount of acceleration:

3. Newton's laws of dynamics.

Great physicist I. Newton. I. Newton debunked the ancient notions that the laws of motion of terrestrial and celestial bodies are completely different. The entire universe is subject to uniform laws that allow mathematical formulation.

Two fundamental problems solved by the physics of I. Newton:

1. Creation of an axiomatic basis for mechanics, which transferred this science to the category of rigorous mathematical theories.

2. Creation of dynamics linking the behavior of the body with the characteristics of external influences on it (forces).

1. Every body continues to be held in a state of rest, or uniform and rectilinear motion, until and insofar as it is compelled by applied forces to change this state.

2. The change in momentum is proportional to the applied force and occurs in the direction of the straight line along which this force acts.

3. An action always has an equal and opposite reaction, otherwise, the interactions of two bodies against each other are equal and directed in opposite directions.

I. Newton's first law of dynamics. Every body continues to be held in a state of rest, or uniform and rectilinear motion, until and insofar as it is compelled by applied forces to change this state.

The concepts of inertia and inertia of a body. Inertia is a phenomenon in which the body tends to maintain its original state. Inertia is the property of a body to maintain a state of motion. The property of inertia is characterized by the mass of the body.

Newton's development of Galileo's theory of mechanics. For a long time it was believed that in order to maintain any movement, it is necessary to carry out an uncompensated external influence from other bodies. Newton shattered these Galileo beliefs.

Inertial frame of reference. Frames of reference, relative to which a free body moves uniformly and rectilinearly, are called inertial.

Newton's first law - the law of inertial systems. Newton's first law is a postulate about the existence of inertial frames of reference. In inertial frames of reference, mechanical phenomena are described most simply.

I. Newton's second law of dynamics. In an inertial frame of reference, rectilinear and uniform motion can occur only if no other forces act on the body or their action is compensated, i.e. balanced. Demonstrated by video demonstration with explanations.

The principle of superposition of forces. Demonstrated by video demonstration with explanations.

The concept of body weight. Mass is one of the most fundamental physical quantities. Mass characterizes several properties of the body at once and has a number of important properties.

Force is the central concept of Newton's second law. Newton's second law specifies that a body will then move with acceleration when a force acts on it. Force is a measure of the interaction of two (or more) bodies.

Two conclusions of classical mechanics from the second law of I. Newton:

1. The acceleration of the body is directly related to the force applied to the body.

2. The acceleration of a body is directly related to its mass.

Demonstration of the direct dependence of the acceleration of a body on its mass

The third law of dynamics of I. Newton. Demonstrated by video demonstration with explanations.

Significance of the laws of classical mechanics for modern physics. Mechanics based on Newton's laws is called classical mechanics. Within the framework of classical mechanics, the motion of not very small bodies with not very high velocities is well described.

Demos:

Physical fields around elementary particles.

Planetary model of the atom by Rutherford and Bohr.

Movement as a physical phenomenon.

Progressive movement.

Uniform rectilinear motion

Uneven relative mechanical movement.

Video animation of reference system.

curvilinear movement.

Path and trajectory.

Acceleration.

Inertia of rest.

The principle of superposition.

Newton's 2nd law.

Dynamometer.

Direct dependence of the acceleration of a body on its mass.

Newton's 3rd law.

Control questions:.

Formulate the definition and scientific subject of physics.

Formulate the physical properties common to all natural phenomena.

Formulate the main stages in the evolution of the physical picture of the world.

Name 2 main principles of modern science.

Name the features of the mechanistic model of the world.

What is the essence of molecular kinetic theory.

Formulate the main features of the electromagnetic picture of the world.

Explain the concept of a physical field.

Determine the signs and differences between electric and magnetic fields.

Explain the concepts of electromagnetic and gravitational fields.

Explain the concept of "Planetary model of the atom"

Formulate the features of the modern physical picture of the world.

Formulate the main provisions of the modern physical picture of the world.

Explain the meaning of A. Einstein's theory of relativity.

Explain the concept: "Mechanics".

Name the main sections of mechanics and give them definitions.

What are the main physical characteristics of movement.

Formulate the signs of translational mechanical motion.

Formulate signs of uniform and non-uniform mechanical motion.

Formulate signs of relativity of mechanical motion.

Explain the meaning of physical concepts: "Reference point and reference system in mechanical motion."

What are the main characteristics of mechanical motion in the frame of reference.

What are the main characteristics of the trajectory of rectilinear motion.

What are the main characteristics of curvilinear motion.

Define the physical concept: "Way".

Define the physical concept: "Scalar quantity".

Reproduce the physical formulas and units of measurement of the characteristics of mechanical movement.

Formulate the physical meaning of the concept: "Acceleration".

Reproduce the physical formula for determining the amount of acceleration.

Name two fundamental problems solved by the physics of I. Newton.

Reproduce the main meanings and content of I. Newton's first law of dynamics.

Formulate the physical meaning of the concepts of inertia and inertia of a body.

What was the development of Galileo's theory of mechanics by Newton.

Formulate the physical meaning of the concept: "Inertial frame of reference".

Why Newton's first law is the law of inertial systems.

Reproduce the main meanings and content of I. Newton's second law of dynamics.

Formulate the physical meanings of the principle of superposition of forces, derived by I. Newton.

Formulate the physical meaning of the concept of body mass.

Explain that force is the central concept of Newton's second law.

Formulate two conclusions of classical mechanics based on the second law of I. Newton.

Reproduce the main meanings and content of I. Newton's third law of dynamics.

Explain the significance of the laws of classical mechanics for modern physics.

Literature:

1. Akhmedova T.I., Mosyagina O.V. Natural science: Textbook / T.I. Akhmedova, O.V. Mosyagin. - M.: RAP, 2012. - S. 34-37.

What is a reference point? What is mechanical movement?

andreus-dad-ndrey

The mechanical motion of a body is the change in its position in space relative to other bodies over time. In this case, the bodies interact according to the laws of mechanics. The section of mechanics that describes the geometric properties of motion without taking into account the causes that cause it is called kinematics.

More generally, motion is any spatial or temporal change in the state of a physical system. For example, we can talk about the motion of a wave in a medium.

* The movement of a material point is completely determined by the change in its coordinates in time (for example, two on a plane). The study of this is the kinematics of the point.
o Rectilinear movement of a point (when it is always on a straight line, the speed is parallel to this straight line)
o Curvilinear movement is the movement of a point along a path that is not a straight line, with arbitrary acceleration and arbitrary speed at any time (for example, movement in a circle).
* The motion of a rigid body consists of the motion of any of its points (for example, the center of mass) and rotational motion around this point. Studied by the kinematics of a rigid body.
o If there is no rotation, then the movement is called translational and is completely determined by the movement of the selected point. Note that this is not necessarily a straight line.
o To describe the rotational movement - the movement of a body relative to a selected point, for example, fixed at a point, use Euler angles. Their number in the case of three-dimensional space is three.
o Also, for a rigid body, a plane movement is distinguished - a movement in which the trajectories of all points lie in parallel planes, while it is completely determined by one of the sections of the body, and the section of the body by the position of any two points.
* Movement of a continuum. It is assumed here that the motion of individual particles of the medium is quite independent of each other (usually limited only by the conditions of continuity of the velocity fields), so the number of defining coordinates is infinite (functions become unknown).
Relativity - the dependence of the mechanical motion of the body on the frame of reference, without specifying the frame of reference - it makes no sense to talk about motion.

Daniel Yuriev

Types of mechanical movement [edit | edit wiki text]
Mechanical motion can be considered for different mechanical objects:
The movement of a material point is completely determined by the change in its coordinates in time (for example, for a plane - by changing the abscissa and ordinate). The study of this is the kinematics of the point. In particular, important characteristics of motion are the trajectory of a material point, displacement, speed and acceleration.
Rectilinear motion of a point (when it is always on a straight line, the speed is parallel to this straight line)
Curvilinear motion - the movement of a point along a trajectory that is not a straight line, with arbitrary acceleration and arbitrary speed at any time (for example, movement in a circle).
The motion of a rigid body consists of the motion of any of its points (for example, the center of mass) and rotational motion around this point. Studied by the kinematics of a rigid body.
If there is no rotation, then the movement is called translational and is completely determined by the movement of the selected point. The movement is not necessarily linear.
To describe the rotational movement - the movement of a body relative to a selected point, for example, fixed at a point - Euler angles are used. Their number in the case of three-dimensional space is three.
Also, for a rigid body, a plane movement is distinguished - a movement in which the trajectories of all points lie in parallel planes, while it is completely determined by one of the sections of the body, and the section of the body is determined by the position of any two points.
Continuum motion. It is assumed here that the motion of individual particles of the medium is quite independent of each other (usually limited only by the conditions of continuity of the velocity fields), so the number of defining coordinates is infinite (functions become unknown).

mechanical movement. Path. Speed. Acceleration

Lara

Mechanical movement is a change in the position of a body (or its parts) relative to other bodies.
The position of the body is given by a coordinate.
The line along which the material point moves is called the trajectory. The length of the trajectory is called the path. The unit of the path is the meter.
Path = speed * time. S=v*t.

Mechanical motion is characterized by three physical quantities: displacement, speed and acceleration.

A directed line segment drawn from the initial position of the moving point to its final position is called displacement (s). Displacement is a vector quantity. The unit of movement is the meter.

Speed ​​is a vector physical quantity that characterizes the speed of movement of a body, numerically equal to the ratio of movement in a small period of time to the value of this period of time.
The speed formula is v = s/t. The unit of speed is m/s. In practice, the speed unit used is km/h (36 km/h = 10 m/s).

Acceleration is a vector physical quantity that characterizes the rate of change in speed, numerically equal to the ratio of the change in speed to the period of time during which this change occurred. Formula for calculating acceleration: a=(v-v0)/t; The unit of acceleration is meter/(square second).

In physics, there is such a thing as mechanical motion, the definition of which is interpreted as a change in the coordinates of a body in three-dimensional space relative to other bodies with the expenditure of time. Oddly enough, but without moving anywhere you can exceed, for example, the speed of a bus. This value is relative and dependent on a given point. The main thing is to fix the reference system in order to observe the point in relation to the object.

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Description

Concepts from physics:

1. A material point is a part of the body or an object with small parameters and mass, which are not taken into account when studying the process. This is a quantity that is neglected in physics.
2. Displacement is the distance traveled by a material point from one coordinate to another. The concept should not be confused with movement, since in physics it is the definition of a path.
3. The path traveled is the area that the item has traveled. What is the distance traveled considers the section of physics under titled "Kinematics".
4. A trajectory in space is a straight or broken line along which an object travels a path. To imagine what a trajectory is, according to the definition from the field of physics, you can mentally draw a line.
5. Mechanical movement is called movement along a given trajectory.

Attention! The interaction of bodies is carried out according to the laws of mechanics, and this section is called kinematics.

Understand what a coordinate system is, and what is a trajectory in practice?

It is enough to mentally find a point in space and draw coordinate axes from it, an object will move relative to it along a broken or straight line, and the types of movement will also be different, including translational, carried out during vibration and rotation.

For example, a cat is in a room, moves to any object, or changes its location in space, moving along different trajectories.

The distance between objects may differ because the selected paths are not the same.

Types

Known types of movement:

1. Translational. It is characterized by the parallelism of two interconnected points moving in the same way in space. An object moves forward when it passes along a single line. It suffices to imagine the replacement of the rod in a ballpoint pen, that is, the rod moves forward along a given path, while each part of it moves in parallel and in the same way. Quite often this occurs in the mechanisms.
2. Rotational. The object describes a circle in all planes that are parallel to each other. The axes of rotation are the centers of the described, and the points located on the axis are fixed. The rotating axis itself can be located inside the body (rotational), and also connected to its outer points (orbital). To understand what it is, you can take a regular needle and thread. Pinch the latter between your fingers and gradually unwind the needle. The needle will describe a circle, and such types of movement should be referred to as orbital. An example of a rotational view: spinning an object on a hard surface.
3. vibrational. All points of a body moving along a given trajectory repeat exactly or approximately in the same time. A good example is a puck suspended on a cord, oscillating to the right and to the left.

Attention! Progressive motion feature. An object moves in a straight line, and in any time interval all its points move in the same direction - this is translational motion. If a bicycle rides, then at any time you can separately consider the trajectory of its any point, it will be the same. It doesn't matter if the surface is flat or not.

These types of movements are encountered daily in practice, so losing them mentally is not difficult.

What is relativity

According to the laws of mechanics, an object moves relative to a point.

For example, if a person is standing still, and the bus is moving, this is called the relativity of the movement of the vehicle in question to the object.

With what speed the object moves in relation to a certain body in space is also taken into account relative to this body and, accordingly, acceleration also has a relative characteristic.

Relativity is a direct dependence of the trajectory given during the movement of the body, the path traveled, the speed characteristic, and also the displacement with respect to reference systems.

How is the countdown

What is a reference system and how is it characterized? The reference in connection with the spatial coordinate system, the primary reference of the time of movement - this is the reference system. In different systems, one body can have a different location.

The point is in the coordinate system, when it starts to move, its movement time is taken into account.

Reference body - this is an abstract object located at a given point in space. When orienting to its position, the coordinates of other bodies are considered. For example, a car is standing still, and a person is moving, in this case, the body of reference is a car.

Uniform movement

The concept of uniform motion - this definition in physics is interpreted as follows.