Technical phenomena in physics. Natural phenomena (biological, physical, chemical)

Man lives in the natural world. You yourself and everything that surrounds you - the air, trees, river, sun - are different natural objects. Changes constantly occur with natural objects, which are called natural phenomena.
Since ancient times, people have tried to understand: how and why various phenomena occur? How do birds fly and why don't they fall? How can a tree float on water and why does it not sink? Some natural phenomena - thunder and lightning, solar and lunar eclipses - frightened people until scientists figured out how and why they occur.
By observing and studying phenomena occurring in nature, people have found application for them in their lives. Observing the flight of birds (Fig. 1), people designed an airplane (Fig. 2).

Rice. 1	Rice. 2

Watching a floating tree, man learned to build ships and conquered the seas and oceans. Having studied the method of movement of the jellyfish (Fig. 3), scientists came up with a rocket engine (Fig. 4). By observing lightning, scientists discovered electricity, without which people today cannot live and work. All kinds of household electrical devices (lighting lamps, televisions, vacuum cleaners) surround us everywhere. Various electric tools (electric drill, electric saw, sewing machine) are used in school workshops and in production.

Scientists divided all physical phenomena into groups (Fig. 6):

Rice. 6

Mechanical phenomena- these are phenomena that occur with physical bodies when they move relative to each other (the revolution of the Earth around the Sun, the movement of cars, the swing of a pendulum).
Electrical phenomena- these are phenomena that arise during the appearance, existence, movement and interaction of electrical charges (electric current, lightning).
Magnetic phenomena- these are phenomena associated with the emergence of magnetic properties in physical bodies (attraction of iron objects by a magnet, turning the compass needle to the north).
Optical phenomena- these are phenomena that arise during the propagation, refraction and reflection of light (reflection of light from a mirror, mirages, the appearance of shadows).
Thermal phenomena- these are phenomena associated with the heating and cooling of physical bodies (boiling a kettle, the formation of fog, the transformation of water into ice).
Atomic phenomena- these are phenomena that arise when the internal structure of the substance of physical bodies changes (the glow of the Sun and stars, an atomic explosion).
Observe and explain. 1. Give an example of a natural phenomenon. 2. To which group of physical phenomena does it belong? Why? 3. Name the physical bodies that participated in physical phenomena.

Biology teacher, MBOU "Secondary School No. 171", Kazan, Sovetsky District, Farida Rinadovna Galyavieva.

Natural history lesson 5th grade on the topic “Phenomena of Nature. Physical phenomena".

Subject: Natural phenomena. Physical phenomena.

Task: To consolidate knowledge about the structure of substances, their properties and varieties of substances;
Formation of knowledge about physical natural phenomena and their diversity.
Developing the ability to observe and perform simple experiments.

Equipment : projector, drawings, tables, photography lesson progress

Organizational stage.
Check students' readiness for the lesson
Updating knowledge .

What is nature?

Name natural phenomena?

Considering the presentation on the topic “Natural phenomena” (rain, snowfall, wind, solar lighting)

Physical phenomena: this is a change in the state, form of a substance, but the composition remains unchanged.
Experience : When heated, pieces of ice begin to melt, forming liquid water. If you continue to boil, steam rises above the pans.
What's going on?

Answer : During the heating process, a solid substance (ice) became liquid, then gaseous.
The substance remains, only its state has changed.

Let's continue the experience : We place cold glass over a pan of boiling water; we notice droplets of water on the surface.
What happened?
Answer : Water changed from a gaseous state to a liquid state when cooled.
Changes in the state of substances are considered physical phenomena.
Water (the substance changed shape to state, but remained the same.)

Even in ancient times, people began to collect information about the world around them, in addition to ordinary curiosity; this was caused by practical needs.
After all, for example, if you know how to lift and move heavy stones, you will be able to build strong walls and build a house that is more comfortable to live in than in a cave or earthen one. And if you learn to smelt metals from ores and make plows and passes, and axes, weapons, you will be able to plow the field better and get a higher harvest, and in case of danger you will be able to protect your land.
Over time, the amount of knowledge about the world around us has increased immeasurably.

Table analysis

Physical phenomena

Examples

Mechanical

Flight of a rocket, falling of a stone, rotation of the Earth around the Sun

Optical

A flash of lightning, the glow of an electric light bulb, the light from the flame of a fire.

Thermal

Melting snow, heating food, burning fuel in an engine cylinder

Sound

The sound of a bell, birdsong, the roar of thunder.

Electromagnetic

Lightning discharge, hair electrification, electric arc

Examples of some physical natural phenomena in the table. Take a look, for example, at the first row of the table.

Question . What can be common between the whip of a rocket, the fall of a drop and the rotation of the planet?
Answers : All examples are described by the same laws - the law of mechanical motion.
Having studied physical phenomena separately, scientists establish their relationship. Thus, a lightning discharge (electromagnetic phenomenon) is necessarily accompanied by a significant increase in temperature in the lightning channel (thermal phenomenon). The study of these phenomena in their interrelation made it possible not only to better understand the natural phenomenon of a thunderstorm, but also to find a way for the practical application of electromagnetic and thermal phenomena. Surely each of you, passing by a construction site, saw workers in protective masks and the dazzling rush of electric welding. Electric welding (a method of joining metal parts using an electric discharge) is an example of the practical use of scientific research.

Let's sum it up

The world around us consists of matter. There are two types of matter: the substance from which all physical bodies are made, and fields.
Changes are constantly taking place in the world that surrounds us. These changes are called phenomena. Thermal, light, mechanical, sound, electromagnetic phenomena are all examples of physical phenomena.

Pins:
1. Can events that occur in a dream or imagination be considered physical phenomena?
2. What substances do the following bodies consist of: textbook, pencil, ball, glass, car?

Homework: prg. 13 read questions and assignments.

About the world around us. In addition to ordinary curiosity, this was caused by practical needs. After all, for example, if you know how to lift
and move heavy stones, you will be able to build strong walls and build a house in which it is more convenient to live than in a cave or dugout. And if you learn to smelt metals from ores and make plows, scythes, axes, weapons, etc., you will be able to plow the field better and get a higher harvest, and in case of danger you will be able to protect your land.

In ancient times, there was only one science - it united all the knowledge about nature that humanity had accumulated by that time. Nowadays this science is called natural science.

Learning about physical science

Another example of an electromagnetic field is light. You will become familiar with some of the properties of light in Section 3.

3. Remembering physical phenomena

The matter around us is constantly changing. Some bodies move relative to each other, some of them collide and, possibly, collapse, others are formed from some bodies... The list of such changes can be continued and continued - it is not without reason that in ancient times the philosopher Heraclitus remarked: “Everything flows, everything changes.” Scientists call changes in the world around us, that is, in nature, a special term - phenomena.

Rice. 1.5. Examples of natural phenomena

Rice. 1.6. A complex natural phenomenon - a thunderstorm can be represented as a combination of a number of physical phenomena

Sunrise and sunset, a snow avalanche, a volcanic eruption, a horse running, a panther jumping - all these are examples of natural phenomena (Fig. 1.5).

To better understand complex natural phenomena, scientists divide them into a collection of physical phenomena - phenomena that can be described using physical laws.

In Fig. Figure 1.6 shows a set of physical phenomena that form a complex natural phenomenon - a thunderstorm. Thus, lightning - a huge electrical discharge - is an electromagnetic phenomenon. If lightning strikes a tree, it will flare up and begin to release heat - physicists in this case talk about a thermal phenomenon. The rumble of thunder and the crackle of flaming wood are sound phenomena.

Examples of some physical phenomena are given in the table. Take a look at the first row of the table, for example. What can be common between the flight of a rocket, the fall of a stone and the rotation of an entire planet? The answer is simple. All examples of phenomena given in this line are described by the same laws - the laws of mechanical motion. Using these laws, we can calculate the coordinates of any moving body (be it a stone, a rocket or a planet) at any point in time that interests us.

Rice. 1.7 Examples of electromagnetic phenomena

Each of you, taking off a sweater or combing your hair with a plastic comb, probably paid attention to the tiny sparks that appeared. Both these sparks and the mighty discharge of lightning belong to the same electromagnetic phenomena and, accordingly, are subject to the same laws. Therefore, you should not wait for a thunderstorm to study electromagnetic phenomena. It is enough to study how safe sparks behave in order to understand what to expect from lightning and how to avoid possible danger. For the first time such research was carried out by the American scientist B. Franklin (1706-1790), who invented an effective means of protection against lightning discharges - a lightning rod.

Having studied physical phenomena separately, scientists establish their relationship. Thus, a lightning discharge (electromagnetic phenomenon) is necessarily accompanied by a significant increase in temperature in the lightning channel (thermal phenomenon). The study of these phenomena in their interrelation made it possible not only to better understand the natural phenomenon of a thunderstorm, but also to find a way for the practical application of electromagnetic and thermal phenomena. Surely each of you, passing by a construction site, saw workers in protective masks and blinding flashes of electric welding. Electric welding (a method of joining metal parts using an electric discharge) is an example of the practical use of scientific research.

4. Determine what physics studies

Now that you have learned what matter and physical phenomena are, it is time to determine what the subject of physics is. This science studies: the structure and properties of matter; physical phenomena and their relationships.

• let's sum it up

The world around us consists of matter. There are two types of matter: the substance from which all physical bodies are made, and the field.

Changes are constantly taking place in the world that surrounds us. These changes are called phenomena. Thermal, light, mechanical, sound, electromagnetic phenomena are all examples of physical phenomena.

The subject of physics is the structure and properties of matter, physical phenomena and their relationships.

• Security questions

What does physics study? Give examples of physical phenomena. Can events that occur in a dream or imagination be considered physical phenomena? 4. What substances do the following bodies consist of: a textbook, a pencil, a soccer ball, a glass, a car? What physical bodies can consist of glass, metal, wood, plastic?

Physics. 7th grade: Textbook / F. Ya. Bozhinova, N. M. Kiryukhin, E. A. Kiryukhina. - X.: Publishing house "Ranok", 2007. - 192 p.: ill.

Ticket No. 1

1. What does physics study? Some physical terms. Observations and experiments. Physical quantities. Measurement of physical quantities. Accuracy and error of measurements.

Physics is the science of the most general properties of bodies and phenomena.

How does a person understand the world? How does he explore natural phenomena, obtaining scientific knowledge about it?

A person receives his very first knowledge from observations behind nature.

To obtain the correct knowledge, sometimes simple observation is not enough and you need to carry out experiment – ​​specially prepared experiment .

Experiments are carried out by scientists a predetermined plan with a specific purpose .

During the experiments measurements are taken using special instruments of physical quantities. Examples physical quantities are: distance, volume, speed, temperature.

So, the source of physical knowledge is observations and experiments.

Physical laws are based and verified on facts established experimentally. An equally important way of knowing is theoretical description of the phenomenon . Physical theories make it possible to explain known phenomena and predict new, not yet discovered ones.

Changes that occur with bodies are called physical phenomena.

Physical phenomena are divided into several types.

Types of physical phenomena:

1. Mechanical phenomena (for example, the movement of cars, airplanes, celestial bodies, fluid flow).

2. Electrical phenomena (for example, electric current, heating of current-carrying conductors, electrification of bodies).

3. Magnetic phenomena (for example, the effect of magnets on iron, the influence of the Earth’s magnetic field on a compass needle).

4. Optical phenomena (for example, reflection of light from mirrors, emission of light rays from various light sources).

5. Thermal phenomena (melting ice, boiling water, thermal expansion of bodies).

6. Atomic phenomena (for example, the operation of atomic reactors, nuclear decay, processes occurring inside stars).

7. Sound phenomena (bell ringing, music, thunder, noise).

Physical terms- these are special words that are used in physics for brevity, certainty and convenience.

Physical body– this is every object around us. (Showing physical bodies: pen, book, desk)

Substance- this is everything that physical bodies are made of. (Showing physical bodies consisting of different substances)

Matter- this is everything that exists in the Universe regardless of our consciousness (celestial bodies, plants, animals, etc.)

Physical phenomena- these are changes that occur with physical bodies.

Physical quantities- these are the measurable properties of bodies or phenomena.

Physical devices– these are special devices that are designed to measure physical quantities and conduct experiments.

Physical quantities:
height h, mass m, path s, speed v, time t, temperature t, volume V, etc.

Units of measurement of physical quantities:

International System of Units SI:

(international system)

Basic:

Length - 1 m - (meter)

Time - 1 s - (second)

Weight - 1 kg - (kilogram)

Derivatives:

Volume - 1 m³ - (cubic meter)

Speed ​​- 1 m/s - (meter per second)

In this expression:

number 10 - numerical value of time,

the letter “s” is an abbreviation for a unit of time (second),

and the combination of 10 s is the time value.

Prefixes to unit names:

To make it more convenient to measure physical quantities, in addition to the basic units, multiple units are used, which are in 10, 100, 1000, etc. more basic

g - hecto (×100) k – kilo (× 1000) M – mega (× 1000 000)

1 km (kilometer) 1 kg (kilogram)

1 km = 1000 m = 10³ m 1 kg = 1000 g = 10³ g

Everything that surrounds us: both living and inanimate nature, is in constant motion and is constantly changing: planets and stars move, it rains, trees grow. And a person, as is known from biology, constantly goes through some stages of development. Grinding grains into flour, falling a stone, boiling water, lightning, glowing a light bulb, dissolving sugar in tea, moving vehicles, lightning, rainbows are examples of physical phenomena.

And with substances (iron, water, air, salt, etc.) various changes or phenomena occur. The substance can be crystallized, melted, crushed, dissolved and again isolated from solution. However, its composition will remain the same.

Thus, granulated sugar can be crushed into a powder so fine that the slightest blow will cause it to rise into the air like dust. Sugar grains can only be seen under a microscope. Sugar can be divided into even smaller parts by dissolving it in water. If you evaporate water from a sugar solution, the sugar molecules again combine with each other to form crystals. But even when dissolved in water or when crushed, sugar remains sugar.

In nature, water forms rivers and seas, clouds and glaciers. When water evaporates, it turns into steam. Water vapor is water in a gaseous state. When exposed to low temperatures (below 0˚C), water turns into a solid state - turns into ice. The smallest particle of water is a water molecule. A water molecule is also the smallest particle of steam or ice. Water, ice and steam are not different substances, but the same substance (water) in different states of aggregation.

Like water, other substances can be transferred from one state of aggregation to another.

When characterizing a substance as a gas, liquid or solid, we mean the state of the substance under normal conditions. Any metal can not only be melted (transformed into a liquid state), but also turned into gas. But this requires very high temperatures. In the outer shell of the Sun, metals are in a gaseous state, because the temperature there is 6000˚C. And, for example, carbon dioxide can be converted into “dry ice” by cooling.

Phenomena in which there is no transformation of one substance into another are classified as physical phenomena. Physical phenomena can lead to a change, for example, in the state of aggregation or temperature, but the composition of substances will remain the same.

All physical phenomena can be divided into several groups.

Mechanical phenomena are phenomena that occur with physical bodies when they move relative to each other (the revolution of the Earth around the Sun, the movement of cars, the flight of a parachutist).

Electrical phenomena are phenomena that occur with the appearance, existence, movement and interaction of electrical charges (electric current, telegraphy, lightning during a thunderstorm).

Magnetic phenomena are phenomena associated with the appearance of magnetic properties in physical bodies (the attraction of iron objects by a magnet, turning the compass needle to the north).

Optical phenomena are phenomena that occur during the propagation, refraction and reflection of light (rainbows, mirages, reflection of light from a mirror, the appearance of shadows).

Thermal phenomena are phenomena that occur during heating and cooling of physical bodies (melting snow, boiling water, fog, freezing of water).

Atomic phenomena are phenomena that occur when the internal structure of the substance of physical bodies changes (the glow of the Sun and stars, an atomic explosion).

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