Physics is the science of nature. Physical bodies and physical phenomena - Knowledge Hypermarket

Lesson Objectives:

• Give an idea about the subject of physics.
• Create an idea of ​​the primary concepts in physics (body, substance, phenomenon).
• Formulate the goals of studying natural phenomena.
• To identify the sources of physical knowledge, to determine the range of phenomena studied, to explain the connection between physics and other sciences and technology.
• To acquaint students with the methods of studying physical phenomena.
• Awaken children's interest in the study of physics and develop curiosity.

Equipment: three rulers of different materials, inclined chute, steel ball, tripod; spring, set of weights; an electric light bulb on a stand, an electrophorous machine, an electric bell, a mirror, a children's machine.

During the classes

Organizing time

Explanation of new material

We begin with you to study the basics of a very interesting and useful science- physics. Getting into a train, taxi, tram, pressing the button of an electric bell, watching a movie or watching a harvester harvest, you hardly thought about how far each of these big and small achievements of technology has gone, how much work has been invested in each of them. . We are accustomed to technology, it has become our companion.

But not very long ago, people rode in horse-drawn chariots, harvested rye and wheat with sickles, sat by the light of burning torches on long winter evenings, and dreamed of various magics only in fairy tales. Gusli-samogudy, carpet-flying, ax-self-cutter? here are the objects of fabulous dreams. Remember, in the fairy tale of A.S. Pushkin, the astrologer and sage, who presented Tsar Dodon with a wonderful cockerel, assured him:

My golden cockerel
Your faithful watchman will be:
As long as everything is peaceful,
So he will sit quietly;
But only a little from the side
Expect war for you
Or a raid of belligerent force,
Or another uninvited misfortune,
Instantly then my cockerel
Raise the comb
Scream and freak out
And in that place will turn around.

And now the dream has come true. Modern radar installations are much better than a golden cockerel. They allow you to instantly and accurately detect aircraft, missiles and other objects in the sky.

As a miracle is said in Yershov's fairy tale "The Little Humpbacked Horse" about cold light:

The flame burns brighter
The hunchback runs faster.
Here he is in front of the fire.
The field shines like daylight.
Wonderful light streams around
But it does not heat, does not smoke.
Ivan was given a diva here,
“What,” he said, “for the devil!
There are five caps in the world,
There is no heat or smoke.
Eco miracle light...”

And now a miracle light in the form of fluorescent lamps penetrated our everyday life. It pleases people on the streets, in shops, in institutions, in the subway, in schools, in enterprises.

Yes, fairy tales become a reality: gusli-samogudy embodied in a tape recorder. Electric saws in a few seconds cut down centuries-old trees better than fabulous self-tapping axes. Not carpets, but airplanes became a widespread means of transport. Our rockets put into orbit artificial earth satellites and spacecraft with astronauts on board. All this was made possible not by the grace of a wizard, but by the skillful application of the achievements of science.

It was difficult for a man millions of years ago,
He didn't know nature at all.
Blindly believed in miracles
He was afraid of everything.
And didn't know how to explain
Storm, thunder, earthquake,
It was difficult for him to live.

And he decided what to be afraid of,
It's better to just know everything.
Intervene on your own
Tell people the truth.
He created the science of the earth,
Briefly called "physics".
Under the name of those short
He recognized nature.

"Physics"- This is a Greek word and in translation means, as you understand, "nature".

One of the most ancient sciences, which allows one to know the forces of nature and put them at the service of man, which makes it possible to understand modern technology and develop it further, is physics. Knowledge of physics is necessary not only for scientists and inventors. Neither an agronomist, nor a worker, nor a doctor can do without them. Each of you will also need them more than once, and many, perhaps, will have a chance to make new discoveries and inventions. What has been done by the work of many scientists and inventors is magnificent. You have already heard the names of many of them: Aristotle, M. Lomonosov, N. Copernicus and many others. But there are still many unresolved tasks ahead: we must put the warmth and light of the Sun at the service of man, learn to accurately predict the weather, predict natural disasters, we must penetrate the vast ocean and terrestrial depths, we must explore and master other planets and star worlds, and much more that is not even in fairy tales.

But for this it is necessary, first of all, to assimilate what has been obtained, in particular, to master the knowledge of physics. Physics - interesting science. It must be studied with great attention, to reach the very essence. However, don't count on easy success. Science is not entertainment, not everything will be fun and entertaining. It requires hard work.

Having received some knowledge, a person formulated a law, used the studied phenomenon in his life, created devices and machines, other auxiliary tools with the help of which he can more successfully and perfectly study and describe other phenomena more deeply. The process of studying physics can be compared to moving up the stairs always up.

Today in the lesson we have to understand and learn the basic physical terms: physical body, substance, physical phenomena, to understand what is the subject of study of physics and how it studies nature.

Physics deals with physical bodies. What would you call the physical body? (Students put forward their assumptions, which I write on the right half of the board. Summarizing the statements, we conclude that the physical body is any subject to be considered in physics.

Name the bodies that surround you. (Give examples.)

What is the difference between the three rulers that I have in my hands?

Class. Made from different materials: wood, plastic, metal.

Teacher. What can be the conclusion?

Class. Bodies can differ in substance.

Teacher. What's happened substance?

Class. It `s that, What is the physical body made of?

Teacher. Give examples of substances that you have on your tables. (Children answer.)

Substance is one of the matter.

Matter is everything that exists in the universe, regardless of our consciousness.

Matter is substance, field.

Any material object is made up of matter. We can touch it and see it. It is more difficult with the field - we can state the consequences of its action on us, but we cannot see it. For example, there is a gravitational field that we do not feel, but thanks to which we walk on the earth and do not fly away from it, despite the fact that it rotates at a speed of 30 km / s, we cannot yet measure it. But the electromagnetic field of a person can not only be felt by the consequences of its impact, but also changed.

In nature, bodies undergo various changes. They are called phenomena. Physical phenomena are called. various changes that occur with physical bodies.

What physical phenomena have you observed? (Students give examples.)

All phenomena are divided into several types: mechanical, thermal, sound, electrical, magnetic, light. Let's consider them on specific examples and experiments. (Some types of phenomena are demonstrated.)

And now let's think together about the following questions: “How do you study physics? What methods are used for this?

- Can observe behind the phenomenon, which we did in the lesson.

- You can do it yourself conduct tests and experiments. At the same time, physicists use their main “weapon” – physical devices. Let's name some of them: clock, ruler, voltmeter,

- Can apply mathematical knowledge

- Definitely needed generalize

Fixing the material

Task 1. Divide the following words into three groups of concepts: chair, wood, rain, iron, star, air, oxygen, wind, lightning, earthquake, oil, compass.

Task 2. You accidentally hid a chocolate bar in your pocket, and it melted there. Can what happened be called a phenomenon? (Yes.)

Task 3. A good wizard appeared to you in a dream, gave you a lot of ice cream, and you treated all your friends to it. Too bad it was just a dream. Can the appearance of a good wizard be considered a physical phenomenon? (Not.)

Task 4. Kolya caught the girls, dipped them into a puddle and carefully measured the depth of each girl's immersion. Tolya just stood nearby and watched the girls flounder. How do Kolya's actions differ from Tolin's, and how do physicists call such actions? (Both physicists and other scientists will call the actions hooliganism. But from the point of view of dispassionate science, Tolya made observations, and Kolya made experiments).

Recording homework§ one ? 3. Answer questions.

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We are surrounded by an infinitely diverse world of substances and phenomena.

It is constantly changing.

Any changes that occur to bodies are called phenomena. The birth of stars, the change of day and night, the melting of ice, the swelling of buds on trees, the flashing of lightning during a thunderstorm, and so on - all these are natural phenomena.

physical phenomena

Recall that bodies are made up of substances. Note that in some phenomena the substances of bodies do not change, while in others they change. For example, if you tear a piece of paper in half, then, despite the changes that have occurred, the paper will remain paper. If the paper is burned, it will turn into ashes and smoke.

Phenomena in which the size, shape of bodies, the state of substances can change, but substances remain the same, do not change into others, are called physical phenomena(evaporation of water, the glow of an electric light bulb, the sound of the strings of a musical instrument, etc.).

Physical phenomena are extremely diverse. Among them are distinguished mechanical, thermal, electrical, lighting and etc.

Let's remember how clouds float across the sky, an airplane flies, a car drives, an apple falls, a cart rolls, etc. In all of these phenomena, objects (bodies) move. Phenomena associated with a change in the position of a body in relation to other bodies are called mechanical(translated from the Greek "mehane" means machine, tool).

Many phenomena are caused by the change of heat and cold. In this case, the properties of the bodies themselves change. They change shape, size, the state of these bodies changes. For example, when heated, ice turns into water, water into steam; When the temperature drops, steam turns into water, water into ice. The phenomena associated with the heating and cooling of bodies are called thermal(Fig. 35).

Rice. 35. Physical phenomenon: the transition of matter from one state to another. If you freeze drops of water, ice will reappear

Consider electrical phenomena. The word "electricity" comes from the Greek word "electron" - amber. Remember that when you quickly take off your woolen sweater, you hear a slight crackle. If you do the same in complete darkness, you will also see sparks. This is the simplest electrical phenomenon.

To get acquainted with another electrical phenomenon, do the following experiment.

Tear off small pieces of paper and place them on the table surface. Comb clean and dry hair with a plastic comb and bring it to the pieces of paper. What happened?

Rice. 36. Small pieces of paper are attracted to the comb

Bodies that are capable of attracting light objects after rubbing are called electrified(Fig. 36). Lightning during a thunderstorm auroras, electrification of paper and synthetic fabrics - all these are electrical phenomena. The operation of the telephone, radio, television, various household appliances are examples of human use electrical phenomena.

Phenomena that are associated with light are called light. Light comes from the sun, stars, lamps, and some living things, such as fireflies. Such bodies are called luminous.

We see when light hits the retina. We cannot see in absolute darkness. Objects that do not themselves emit light (for example, trees, grass, the pages of this book, etc.) are visible only when they receive light from some luminous body and reflect it from their surface.

The moon, which we often speak of as a night light, is in reality only a kind of reflector of sunlight.

By studying the physical phenomena of nature, man has learned to use them in Everyday life, life.

1. What are called natural phenomena?

2. Read the text. List what natural phenomena are called in it: “Spring has come. The sun is getting hotter. Snow melts, streams run. Buds swelled on the trees, rooks flew in.

3. What phenomena are called physical?

4. From the physical phenomena listed below, write down the mechanical phenomena in the first column; in the second - thermal; in the third - electrical; in the fourth - light phenomena.

Physical phenomena: lightning flash; snow melting; coast; melting of metals; operation of an electric bell; rainbow in the sky; sunbeam; moving stones, sand with water; boiling water.

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The natural world around us is simply teeming with various secrets and mysteries. Scientists have been looking for answers for centuries and sometimes trying to explain, but even the best minds of mankind still defy some amazing natural phenomena.

Sometimes one gets the impression that incomprehensible flashes in the sky, spontaneously moving stones do not mean anything special. But, delving into the mysterious manifestations observed on our planet, you understand that it is impossible to answer many questions. Nature carefully hides its secrets, and people put forward new hypotheses, trying to unravel them.

Today we will look at physical phenomena in wildlife that will make you take a fresh look at the world around us.

physical phenomena

Every body is made up of certain substances, but note that different actions affect the same bodies differently. For example, if paper is torn in half, paper will remain paper. But if you set it on fire, then the ashes will remain from it.

When the size, shape, state changes, but the substance remains the same and does not transform into another, such phenomena are called physical. They may be different.

Natural phenomena, examples of which we can observe in ordinary life, are:

• Mechanical. The movement of clouds across the sky, the flight of an airplane, the fall of an apple.
• Thermal. caused by temperature changes. In the course of this, the characteristics of the body change. If you heat ice, it becomes water, which turns into steam.
• Electrical. Surely at fast withdrawal Have you ever heard a specific crackle from your woolen clothes, similar to an electric discharge. And if you do all this in a dark room, you can still observe sparks. Objects that, after friction, begin to attract lighter bodies are called electrified. Northern lights, lightning during a thunderstorm are prime examples
• light. body, emitting light, called This includes the Sun, lamps and even representatives of the animal world: some species of deep-seated fish and fireflies.

The physical phenomena of nature, examples of which we have considered above, are successfully used by people in everyday life. But there are those that still excite the minds of scientists and cause universal admiration.

Northern Lights

Perhaps this rightfully bears the status of the most romantic. High in the sky, multi-colored rivers form, which cover an endless number of bright stars.

If you want to enjoy this beauty, then it is best to do it in the northern part of Finland (Lapland). There was a belief that the cause of the occurrence was the wrath of the supreme gods. But the legend of the Sami people about the fabulous fox, which hit its tail on the snow-covered plains, was more popular, because of which colored sparks soared up and lit up the night sky.

Clouds in the form of pipes

Such a phenomenon of nature can drag any person into a state of relaxation, inspiration, illusions for a long time. Such sensations are created due to the shape of large pipes that change their shade.

You can see it in those places where a storm front begins to form. This natural phenomenon is most often observed in countries with a tropical climate.

Stones that move in Death Valley

There are various natural phenomena, examples of which are quite explainable from a scientific point of view. But there are some that defy human logic. One of the mysteries of nature is considered. This phenomenon can be observed in the American national park called Death Valley. Many scientists try to explain the movement by strong winds, which are often found in desert areas, and by the presence of ice, since it was in winter that the movement of stones became more intense.

During the research, scientists made observations of 30 stones, the weight of which was no more than 25 kg. In seven years, 28 out of 30 boulders moved 200 meters from the starting point.

Whatever the guesses of scientists, they do not have a definite answer regarding this phenomenon.

Ball lightning

Appearing after a thunderstorm or during it, is called ball lightning. There is an assumption that Nikola Tesla managed to create in his laboratory fireball. He wrote that he had not seen anything like this in nature (it was about fireballs), but he figured out how they form, and even managed to recreate this phenomenon.

Modern scientists have not been able to achieve such results. And some even question the existence of this phenomenon as such.

We have considered only some natural phenomena, examples of which show how amazing and mysterious our world around us is. How much more unknown and interesting we have to learn in the process of development and improvement of science. How many discoveries await us ahead?

Physical bodies are actors» physical phenomena. Let's get acquainted with some of them.

mechanical phenomena

Mechanical phenomena are the movement of bodies (Fig. 1.3) and their action on each other, for example, repulsion or attraction. The action of bodies on each other is called interaction.

We will get acquainted with mechanical phenomena in more detail this academic year.

Rice. 1.3. Examples of mechanical phenomena: movement and interaction of bodies during sports competitions (a, b. c); the movement of the Earth around the Sun and its rotation around its own axis (r)

sound phenomena

Sound phenomena, as the name suggests, are phenomena associated with sound. These include, for example, the propagation of sound in air or water, as well as the reflection of sound from various obstacles - say, mountains or buildings. When sound is reflected, a familiar echo is produced.

thermal phenomena

Thermal phenomena are the heating and cooling of bodies, as well as, for example, evaporation (turning liquid into vapor) and melting (turning solid body into liquid).

Thermal phenomena are extremely widespread: for example, they cause the water cycle in nature (Fig. 1.4).

Rice. 1.4. The water cycle in nature

heated sunbeams the water of the oceans and seas evaporates. Rising, the vapor cools, turning into water droplets or ice crystals. They form clouds from which water returns to Earth in the form of rain or snow.

The real "laboratory" of thermal phenomena is the kitchen: whether soup is cooked on the stove, whether water boils in a kettle, whether food is frozen in the refrigerator - all these are examples of thermal phenomena.

Thermal phenomena also determine the operation of an automobile engine: when gasoline is burned, a very hot gas is formed that pushes a piston (a part of the motor). And the movement of the piston through special mechanisms is transmitted to the wheels of the car.

Electrical and magnetic phenomena

The most striking (in the literal sense of the word) example of an electrical phenomenon is lightning (Fig. 1.5, a). Electric lighting and electric transport (Fig. 1.5, b) became possible through the use of electrical phenomena. Examples of magnetic phenomena are the attraction of iron and steel objects by permanent magnets, as well as the interaction of permanent magnets.

Rice. 1.5. Electrical and magnetic phenomena and their uses

The compass needle (Fig. 1.5, c) turns so that its “north” end points north precisely because the needle is a small permanent magnet, and the Earth is a huge magnet. The northern lights (Fig. 1.5, d) are caused by the fact that electrically charged particles flying from space interact with the Earth as with a magnet. Electrical and magnetic phenomena determine the operation of televisions and computers (Fig. 1.5, e, f).

optical phenomena

Wherever we look, we will see optical phenomena everywhere (Fig. 1.6). These are phenomena associated with light.

An example of an optical phenomenon is the reflection of light by various objects. Rays of light reflected by objects enter our eyes, thanks to which we see these objects.

Rice. 1.6. Examples of optical phenomena: The sun emits light (a); The moon reflects sunlight (b); especially well reflect the light of the mirror (c); one of the most beautiful optical phenomena - a rainbow (d)

Topic: General concepts about dangerous and emergency situations natural character.

Lesson topic: Natural phenomena and their classification.

The purpose of the lesson: To acquaint students with natural phenomena and their diversity.

Lesson objectives:

I. Educational tasks:

• Recall and consolidate knowledge about the shells of the Earth.
• To form students' knowledge that the formation of any natural phenomenon is associated with the processes occurring in the Earth's shells.
• Give general idea, students about the types of natural phenomena at the place of their occurrence.

II. development tasks.

• To develop in students the ability and ability to foresee the natural phenomena of their area, which can lead to serious consequences, as well as ways to protect against them.

III. educational tasks.

• To instill in students the belief that any natural phenomenon destructive power causes great damage to the state different kind, primarily material and loss of life. Therefore, the state needs to send funds to scientific institutions so that they deal with this problem and be able to predict them in the future.

During the classes

Teacher: Today, children, we will talk about natural phenomena and their diversity. Of course, you know some, some you learned from the course of natural history and geography, and if someone is interested in the media, then from there. If you turn on the TV, radio or use the Internet, then we can say with confidence that natural phenomena of destructive power are occurring more and more often, and their strength is becoming greater. Therefore, we need to know what natural phenomena occur, where they occur most often and how to protect ourselves from them.

Teacher: And so let's remember from the course of geography what shells of the Earth exist.

In total, 4 shells of the Earth are distinguished:

1. The lithosphere is made up of the earth's crust and top part mantle.
2. The hydrosphere is a water shell, it includes all water in different states.
3. The atmosphere is a gas shell, the lightest and most mobile.
4. The biosphere is the sphere of life, it is the area of ​​existence of all living organisms.

Teacher: In all these shells, certain processes take place, as a result of which natural phenomena arise. Therefore, various natural phenomena can be divided according to the place of their occurrence:

Teacher: From this diagram, we see how many natural phenomena exist. Now let's look at each of them and find out what they are. (Children should take an active part in this part.)

Geological.

1. An earthquake is a natural phenomenon associated with geological processes occurring in the Earth's lithosphere, it manifests itself in the form of tremors and vibrations of the earth's surface resulting from sudden displacements and ruptures in the earth's crust or in the upper part of the mantle.

Picture 1.

2. A volcano is a conical mountain, from which an incandescent substance, magma, erupts from time to time.

A volcanic eruption is the release of molten matter from the planet's surface. earth's crust and the Earth's mantle, which is called magma.

Figure 2.

3. A landslide is a downward displacement of soil masses under the action of gravity, which occurs on slopes when the stability of the soil or rocks is disturbed.

The formation of landslides depends on various factors such as:

• what rocks make up this slope;
• slope steepness;
• ground water, etc.

Landslides can occur as naturally(e.g. earthquake, heavy rainfall) and artificially (e.g. human activities: deforestation, excavation).

Figure 3

4. Collapse is the separation and fall of large masses of rocks, their overturning, crushing and rolling on steep and steep slopes.

Causes of landslides in the mountains can be:

• the rocks that make up the mountains are layered or broken by cracks;
• water activity;
• geological processes (earthquake), etc.

Causes of collapses on the coast of seas and rivers are the washing and dissolution of the underlying rocks.

Figure 4

5. An avalanche is a collapse of a mass of snow on mountain slopes, the angle of inclination should be at least 15 °.

The causes of an avalanche are:

• earthquake;
• intensive snow melting;
• prolonged snowfall;
• human activity.

Figure 5

Meteorological.

1. A hurricane is a wind whose speed exceeds 30 m/s, resulting in huge destruction.

Figure 6

2. A storm is a wind, but with a lower speed than in a hurricane and is no more than 20 m/s.

Figure 7

3. A tornado is an atmospheric vortex that forms in a thundercloud and descends, has a funnel or sleeve head start.

A tornado consists of a core and a wall. Around the core there is an upward movement of air, the speed of which can reach 200 m / s.

Figure 8

Hydrological.

1. Flooding is a significant flooding of the area as a result of a rise in the water level in a lake, river, etc.

Reasons for the flood:

• intensive snowmelt in spring;
• heavy rainfall;
• blockage of the riverbed rocks during an earthquake, collapse, etc., as well as ice during traffic jams;
• wind activity (water surge from the sea, bay at the mouth of the river).

Types of floods:

Figure 9

2. Mudflow is a stormy stream in the mountains of a temporary nature, consisting of water and a large number fragments of rocks.

The formation of mudflows is associated with abundant precipitation in the form of rain or intense snowmelt. As a result, loose rocks are washed away and move along the river bed with high speed, which picks up everything in its path: boulders, trees, etc.

Figure 10.

3. Tsunami is a type of sea waves resulting from the vertical shift of large areas of the seabed.

A tsunami occurs as a result of:

• earthquakes;
• underwater volcano eruptions;
• landslides, etc.

Figure 11.

Biological.

1. A forest fire is an uncontrolled burning of vegetation, spontaneously spreading through a forest area.

Forest fire can be: grassroots and riding.

An underground fire is the burning of peat in marshy and swampy soils.

Figure 12.

2. An epidemic is a spread infectious disease among a large number of the population and significantly exceeding the incidence rate usually recorded in the area.

Figure 13.

3. An epizootic is a widespread infectious disease among animals (for example: foot-and-mouth disease, swine fever, bovine brucellosis).

Figure 14.

4. Epiphytotics are mass distribution infectious disease among plants (for example: late blight, wheat rust).

Figure 15.

Teacher: As you can see, in the world there are a huge number of phenomena that surround us. So let's remember them and be extremely careful at the time of their occurrence.

Some of you may say: “Why do we need to know all of them if they are not typical for our region?”. From one point of view you are right, but from the other you are wrong. Each of you tomorrow, the day after tomorrow or in the future will surely go on a trip to other parts of the Motherland and the country. And there, as you know, there can be completely different phenomena that are not typical for our area. And then your knowledge will help you survive in a critical situation and avoid negative consequences. As the saying goes: "God saves the safe."

Literature.

1. Smirnov A.T. Fundamentals of life safety. 7th grade.
2. Shemanaev V.A. Teaching practice in the system of modern teacher training.
3. Smirnov A.T. The program of educational institutions of the basics of life safety grades 5-11.