Phenomenon" (7th grade). Didactic material for the physics lesson "Body. Substance. Phenomenon" (7th grade) Reinforcing the topic "Structure of Matter"
If I wanted to read, I haven't yet
knowing the letters, this would be nonsense.
In the same way, if I wanted to judge
about natural phenomena, without having any
ideas about the beginnings of things, this
it would be just as nonsense.
M. V. Lomonosov
Look around you. What a variety of objects surrounds you: people, animals, trees. This is a TV, a car, an apple, a stone, a light bulb, a pencil, etc. It is impossible to list everything. In physics any object is called a physical body.
Rice. 6
How are physical bodies different? A lot of people. For example, they can have different volumes and shapes. They can consist of different substances. Silver and gold spoons (Fig. 6) have the same volume and shape. But they consist of different substances: silver and gold. The wooden cube and ball (Fig. 7) have different volumes and shapes. These are different physical bodies, but made of the same substance - wood.
Rice. 7
In addition to physical bodies, there are also physical fields. Fields exist independently of us. They cannot always be detected using human senses. For example, the field around a magnet (Fig. 8), the field around a charged body (Fig. 9). But they are easy to detect using instruments.
Rice. 8
Rice. 9
Various changes can occur with physical bodies and fields. A spoon dipped into hot tea heats up. The water in the puddle evaporates and freezes on a cold day. The lamp (Fig. 10) emits light, the girl and the dog are running (moving) (Fig. 11). The magnet becomes demagnetized and its magnetic field weakens. Heating, evaporation, freezing, radiation, movement, demagnetization, etc. - all these changes occurring with physical bodies and fields are called physical phenomena.
Rice. 10
By studying physics, you will become familiar with many physical phenomena.
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Physical quantities are introduced to describe the properties of physical bodies and physical phenomena. For example, you can describe the properties of a wooden ball and cube using physical quantities such as volume and mass. A physical phenomenon - movement (of a girl, a car, etc.) - can be described by knowing such physical quantities as path, speed, period of time. Pay attention to the main sign of a physical quantity: it can be measured using instruments or calculated using the formula. The volume of a body can be measured with a beaker of water (Fig. 12, a), or by measuring the length a, width b and height c with a ruler (Fig. 12, b), it can be calculated using the formula
V = a. b. c.
All physical quantities have units of measurement. You have heard about some units of measurement many times: kilogram, meter, second, volt, ampere, kilowatt, etc. You will become more familiar with physical quantities in the process of studying physics.
Rice. 12
Think and answer
- What is called the physical body? A physical phenomenon?
- What is the main sign of a physical quantity? Name the physical quantities known to you.
- From the above concepts, name those that relate to: a) physical bodies; b) physical phenomena; c) physical quantities: 1) drop; 2) heating; 3) length; 4) thunderstorm; 5) cube; 6) volume; 7) wind; 8) drowsiness; 9) temperature; 10) pencil; 11) period of time; 12) sunrise; 13) speed; 14) beauty.
Homework
We have a “measuring device” in our bodies. This is a heart with which you can measure (with not very high accuracy) a period of time. Determine by your pulse (the number of heartbeats) the time period for filling a glass with tap water. Consider the time of one blow to be approximately one second. Compare this time with the clock readings. How different are the results obtained?
1. Indicate what refers to the concept of “physical body” and what to the concept of “substance”:
2. Indicate the substances that make up bodies:scissors, glass, shovel, pencil
Horizontally: 1. Change in nature. 2. Science of nature. 3. Everything that exists in the Universe regardless of human consciousness. 4.Ancient Greek scientist. 5. Source of knowledge.
Vertically:
A special device for measuring physical Quantities. 2. Russian scientist. 3. Any subject studied in physics
Name physical bodies that can be made from
porcelain, rubber .
2. Fill the table:
Physical body
Substance
Phenomenon
Lead, thunder, rails, blizzard, aluminum, dawn, Mercury, scissors, shot, earthquake
It’s getting cold, the ball is rolling, thunder is heard, dawn is coming, the lamp is on, the water is boiling, the car is slowing down.
1. Name the physical bodies that can be made fromsteel, plastic
2. Fill out the table:
Physical body
Substance
Phenomenon
Mercury, snowfall, table, copper, helicopter, oil, boiling, blizzard, Earth, flood
3. Determine the type of physical phenomenon:
The snow is melting, the clouds are moving, the stars are twinkling, a log is floating, there is an echo, leaves are rustling, lightning is flashing
Lesson objectives:
- Give an idea of the subject of physics.
- Create an idea of the primary concepts in physics (body, matter, phenomenon).
- Formulate the goals of studying natural phenomena.
- Identify sources of physical knowledge, determine the range of phenomena being studied, explain the connection of physics with other sciences and technology.
- To familiarize students with methods for studying physical phenomena.
- Arouse children's interest in studying physics and develop curiosity.
Equipment: three rulers made of different materials, an inclined chute, a steel ball, a tripod; spring, set of weights; electric light bulb on a stand, electrophore machine, electric bell, mirror, children's car.
During the classes
Organizing time
Explanation of new material
We are starting to study the basics of a very interesting and useful science - physics. Getting on a train, taxi, tram, pressing an electric bell, watching a movie or watching a combine harvest, you hardly thought about how far each of these large and small technological achievements has gone, how much work has been put into each of them . We are accustomed to technology; it has become our companion.
But not very long ago, people rode in horse-drawn carriages, reaped rye and wheat with sickles, sat in the light of burning splinters on long winter evenings and only dreamed of various magics in fairy tales. Samoguda gusli, flying carpet, self-chopping axe? These are the objects of fairy-tale dreams. Remember, in the fairy tale by A.S. Pushkin, the astrologer and sage, who gave King Dodon a wonderful cockerel, assured him:
My golden cockerel
Your faithful watchman will be:
If everything around is peaceful,
So he will sit quietly;
But only a little from the outside
Expect war for you
Or the onslaught of battle force,
Or another uninvited misfortune,
Instantly then my cockerel
Raises the comb
Screams and starts up
And it will turn back to that place.
And now the dream has come true. Modern radar installations are much better than the golden cockerel. They allow you to instantly and accurately detect airplanes, missiles and other objects in the sky.
How a miracle is spoken of in Ershov’s fairy tale “The Little Humpbacked Horse” about cold light:
The flame burns brighter
The little hunchback runs faster.
Here he is in front of the fire.
The field shines as if it were day.
A wonderful light flows all around,
But it doesn’t heat up, it doesn’t smoke.
Ivan was amazed here,
“What,” he said, “what kind of devil is this!”
There are about five hats in the world,
But there is no heat and no smoke.
Eco miracle light...”
And then a miracle light in the form of fluorescent lamps penetrated into our everyday life. It makes people happy on the streets, in shops, in institutions, in the subway, in schools, in enterprises.
Yes, fairy tales are becoming reality: samogud harps have become a tape recorder. Electric saws cut down centuries-old trees in a few seconds better than fairy-tale self-cutting axes. Not carpets, but airplanes became a widespread means of transport. Our rockets launch artificial Earth satellites and spaceships with astronauts on board into orbit. All this became possible not by the grace of a wizard, but on the basis of the skillful application of scientific achievements.
It was difficult for man millions of years ago,
He didn't know nature at all
Blindly believed in miracles
He was afraid of everything, everything.
And I didn't know how to explain
Storm, thunder, earthquake,
It was difficult for him to live.
And he decided, why be afraid?
It's better to just find out everything.
Intervene in everything yourself,
Tell people the truth.
He created the science of the earth,
Briefly called it “physics”.
Under the title that short
He recognized nature.
"Physics"– this is a Greek word and translated means, as you understand, “nature”.
One of the oldest sciences, which makes it possible to understand 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 the opportunity to make new discoveries and inventions. What has been accomplished through 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 unsolved tasks ahead: it is necessary to put the warmth and light of the Sun at the service of man, to learn to accurately predict the weather, to predict natural disasters, it is necessary to penetrate the vast ocean and earthly depths, it is necessary to explore and develop other planets and star worlds, and much more that does not exist even in fairy tales.
But to do this, you must first of all master what you have acquired, in particular, master knowledge of physics. Physics is an interesting science. It must be studied with great attention, to get to the very essence. However, don't expect easy success. Science is not entertainment, not everything will be fun and entertaining. It requires persistent work.
Having received some knowledge, a person formulated a law, used the studied phenomenon in his life, created instruments and machines, and other auxiliary tools with the help of which he can more successfully and more perfectly study and describe other phenomena more deeply. The process of studying physics can be compared to moving up the stairs.
Today in the lesson we have to understand and master the basic physical terms: physical body, matter, physical phenomena, understand what is the subject 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 down on the right half of the board. Summarizing the statements, we come to the conclusion that a physical body is any object subject to consideration in physics.
Name the bodies that surround you. (Give examples.)
How are the three rulers in my hands different from each other?
Class. Made from different materials: wood, plastic, metal.
Teacher. What can be concluded?
Class. Bodies can differ in substance.
Teacher. What's happened substance?
Class. This is what, what the physical body is made of.
Teacher. Give examples of substances that are on your tables. (Children answer.)
Substance is one of the types matter.
Matter- this is everything that exists in the Universe, regardless of our consciousness.
Matter – substance, field.
Any material object consists of matter. We can touch it and see it. It’s 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 influence, but also changed.
In nature, bodies undergo various changes. They are called phenomena. Physical phenomena are called. various changes occurring in physical bodies.
What physical phenomena did you observe? (Students give examples.)
All phenomena are divided into several types: mechanical, thermal, sound, electrical, magnetic, light. Let's look at them using specific examples and experiments. (Some types of phenomena are demonstrated.)
Now let’s think together about the following questions: “How do they study physics? What methods are used for this?”
- Can observe behind the phenomenon, which is what we did in class.
- You can do it yourself carry out experiments and experiments. At the same time, physicists use their main “weapons” – physical instruments. Let's name some of them: clock, ruler, voltmeter,
- Can apply mathematical knowledge
- Definitely necessary make generalizations
Fixing the material
Problem 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 kind wizard appeared to you in a dream, gave you a lot of ice cream, and you treated all your friends to it. It's just a pity that it was a dream. Can the appearance of a good wizard be considered a physical phenomenon? (No.)
Task 4. Kolya caught the girls, dipped them into a puddle and carefully measured the depth of each girl’s dive. Tolya just stood nearby and watched the girls flounder. How do Kolin’s actions differ from Tolin’s, and what 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 performed experiments).
Recording homework § 1? 3. Answer questions.
