Open physics lesson friction force. Development of a lesson in physics on the topic: "Friction force". Ways to reduce friction

MBOU "Mottable Oosh"

The lesson developed a physician teacher:

Leontiev N. A.

2013

Objectives lesson:

Educational:

Formation of finances about the power of friction,

Study the causes and types of friction,

Reveal the nature of friction strength

Experimentally establish, from which the friction force depends.

Developing:

Develop observation, attention, ability to analyze, compare the results, draw conclusions;

Develop the skills of practical work.

Develop creative activity using curiosity as an incentive of cognitive activity.

Raising:

To promote the formation of the idea idea of \u200b\u200bthe cognition of the phenomena and the properties of the surrounding world.

Create a success situation for each student.

Equipment:

dynamometers, planes, bars covered with different materials, a set of cargo, a computer with a multimedia projector.

Expected results:

This lesson makes it possible to deepen knowledge on the subject for each student to understand the processes occurring around us.

DURING THE CLASSES

1. Organizational stage. (Slide number 1)

Teacher. Good afternoon dear friends! I am glad to see you, let's welcome our guests and start working. On the way today I met the postman, he asked to give you a letter from Santa Claus. I am so curious, I was so suffered from finding out what we were talking about in this letter. And you? Will you allow me to read it?

2. Preparation of students to work at the main stage of the lesson.

MOTIVATION

Teacher. (reads a letter). " Dear Guys! I write a letter to you in the hope that you will help me, soon a new year, and I have to deliver the New Year's gifts to everyone who has about himself in the course of the year. But, unfortunately, now I can not leave my house. First, my new silk bag is constantly unleashed, and I am afraid on the way to lose all gifts. Secondly, my sleigh can not move on the ground without snow, December is not very snowy. I ask you, help me, give advice how to get out of this situation. I look forward to your answers. Santa Claus”.

And you know, we can help Santa Claus! We will give him an answer, but under one condition: if at today's lesson, we will reveal one very important secret, the name of which you will find yourself, if you correctly answer the crossword questions.

3. Actualization (Slide 2)

Teacher. Guess the crossword. 1. One unit. 2. Phenomenon Saving body velocity in the absence of action on it other bodies. 3. The force with which the body due to attraction to the Earth acts on the support or suspension. 4. Device for measuring force, 5. Physical value. Characterizing the effect of bodies on each other, 6, the smallest particle of the substance.

4. Studying a new material.

Teacher. So, we learned the name of the mystery - friction. This phenomenon accompanies us literally at every step and therefore has become familiar and imperceptible. And it is characterized by the force of friction. The strength of friction will be discussed at today's lesson. So, write the date and topic of the lesson(Slide 3): "Friction force".

Tell me, what are you already known to you?

Students . Gravity. The power of world gravity. The power of elasticity. Body weight.

Teacher. What does the result of the action depend on?

Students.

• from direction
• numerical value
• application points.

Teacher. The result of friction strength also depends on what body is attached to this force where it is directed and which is numerical value. The purpose of today's lesson will be to prove it.(Slide 4).

Teacher. What happened with the speed of the car, the cat was fought?

Students. She has changed.

Teacher. What is the reason for changing speed?

Students. There is power on it.

Teacher. How is this power sent?

Students. Against movement.

Teacher. Why do you think so?

Students. If it were directed towards movement, the vehicle speed would increase. And since the speed decreases, it means that the force is directed against the movement.

Teacher. The force about which is in question is called the force of friction. It is always directed against the movement of the body under consideration along the surface of another. Let's formulate the definition of friction strength and write it to the notebook.(Slide 5)

Force, arising when the surfaces of the surfaces occur in contact and impeding them to move relative to each other calledfriction force. And denotes f tr. (Slide 6)

Teacher. Let's find out what the cause of the friction force occurs, and

find out the reason for the occurrence of friction force will help the textbook (p. 71)

• Roughness of surfaces.(Slide 7)

• Under perfectly smooth surfaces, a mutual attraction arises between molecules of touching bodies. (Slide 8)

Teacher. Well done, yes, the guys with rough surfaces friction is mainly due to the first cause, and with very smooth surfaces the molecular nature of friction affects. Let's write it to the notebook.

Teacher. We will conduct a small experiment, as a result of which we find out what kinds of friction force are there:

(Slides)

Teacher. With the help of a textbook, create an inclined plane, place a bar on it. When the body is alone on the inclined plane, it is held on it by friction. Indeed, if not friction, the body under the action of gravity would slip down the inclined plane.
The friction force arising between the bodies resting relative to each other is calledthe strength of rest friction.

People's friction force keeps the nail, driven into the board, does not allow to unleash the bow on the ribbon and others.

Teacher. Pull the thread attached to the bar. Try to pull uniformly, parallel to the surface of the table. When sliding one body over the surface of another friction occurs, which is calledfriction slip. For example, the movement of the sleigh in the snow.

Teacher. Place a pencil bar, handles, pull the thread.
If one body does not slide, and rolls over the surface of another, the friction arising from this is calledfriction rolling. For example, the movement of the wheels of the machine.

Teacher. And now we write, what types of friction strength we learned.(Slide with types of friction force)

Teacher. What from the forces of friction the greatest, and what is the smallest?(Slide 19 with output)

Demonstration (With the same corner of the plane inclination, we consider the movement of a pencil with friction rolling and friction of sliding)

Teacher . What is the power of friction more? F.tr. Slip. or f tr. rolling

Students. Rolling stock

5. Fizkultminthka for the eyes.

- Guys, see how much we have learned about the strength of friction. Tired?

- brew palm;
how to deal with flu virus? - Stimulate immunity!
- swelling the uches, in which there are biologically active points affecting immunity;
- To relax your back muscles, swells along the spine, to improve blood circulation in these muscles.
- Walk: 3 steps forward and three backwards.

– Thank you, sit down.

6. Frontal experiment

Teacher. And now the guys will be divided into groups and spend the proposed experiments in each group at the end of work you need to make the conclusion from what the force of friction depends. (Slide 20)

But before you start checking the hypotheses, I want to ask you how you can measure the strength of friction?

Experience is carried out - Teacher:

- We evenly move the bar using a dynamometer. What strengths act on the line on the line?(Thrust and friction force)
- If the speed of movement is constant, what can be said about the automatic strength of these forces?(It is zero).
- What is the power of friction of slip?(It is equal to the absolute value of the strength of the thrust, which the dynamometer shows)

The class is divided into groups of 4 people.

1 group - on the table Wooden ruler, tribometer, dynamometer.

(Students establish addiction of friction force from surface area.)

Students. The friction force does not depend on the surface area.

2 Group - on the table Dry ruler and line coated with a layer of Vaseline Tribeter and tribeometr with attached sandpaper, dynamometer. (The dependence of friction force from lubrication is established.)

Students. When using lubrication, friction force is less.

3 Group - on the table line Tribeter, cargo. (The dependence of the friction force on force presses the body to the surface is established.)

4 Group - on the table Tribeter, ruler, ruler with sandpaper, tribeleter with sandpaper, dynamometer. (Dependence on the genus of rubbing surfaces is established.)

(Slide 21 with an outcome from which the force of friction depends)

Friction force:

Students. Friction force depends on from the kind of rubbing surfaces

Teacher. Guys, life experience tells us that friction is very important in our lives and plays both a positive and negative role.

1. The wisdom and life experience of any people concludes the proverbs and sayings.
For example:

• Not fit, you will not fight
• It went like oh oil
• What is circle - easy to roll
• Ski slide on the weather
• There is no such person who would not have slipped on ice at least once.

(Slides 22, 23, 24, 25, 26, 27 with useful and harmful friction force)

Teacher. Guys, but at the end of our lesson, let's summarize what we learned about the strength of friction today?(Slide 28).

Well, when we all found out about very important for our life, the strength of friction, what would you advise our Santa Claus?

Students. Change the bag to the grinkic, such as plush or stem. If there is no snow, then transfer from the sleigh on the cart or carriage. Since rolling friction force is less than the force of slip friction.

7. Fastening (slide 29)

Teacher. And now the guys let's answer the test questions that I give you

prepared.

TEST

P. rolling friction force
W. slip friction force
IN. the strength of friction rest

C. increases
D. does not change
E. decrease

A. in motion
P. against movement
N. does not have directions

I. not changing
E. decrease
W. increases

K. 15 KN
L. 300 KN
H. 150 kN.

Table of answers

Check the answers. Who got the code word "success"? Izotovil .

8. Homework: (Slide 30)

Answer in writing in the notebook to the question: if the friction force disappeared so that we shouted the "hurray" or "guard"?

Literature:

• Schoolboy's directory. Physics. - M.: Philological Society "Word", Pries A.V. Physics-7 ed. - M.: Drop, 2004.
• Zubkov L.A. Friction force. - Physics (PS), 1998, No. 2. Ed.d.D. The first of September - Physics No.21 2007

Lesson - Traveling on the topic: "Friction force"

Plan abstract lesson in physics

Class: Grade 7

Program section: "Interaction bodies."

Type of lesson: Lesson assimilation of new knowledge.

View: combined lesson.

Technology: personally oriented.

Objectives lesson:

1. Didactic: create conditions for the assimilation of a new educational material using informational technologies and elements of cooperation technology.
2. Educational:acquaint students with friction phenomenon, form a conceptfriction force , consider the types of friction, to experimentally establish, from which this force depends, find out the causes of the friction force.
3. Developing: develop high-quality student scope; develop logical thinking; form an idea of \u200b\u200bthe process of scientific knowledge; Development of skills to experiment; form the ability to use the instruments; analyze, compare the results of experiments; Continue forming the skills to design a support abstract.
4. Educational: We instill a culture of mental work.
5. Motivational: indiscover interest to the study of the subject.

Equipment for the teacher:computer, multimedia presentation "friction force", toy car, sand, wooden bar with thread, pen, dynamometer, glass plates - 2 pcs, reference abstract "friction force".

Equipment for students:dynamometer, a sheet of smooth and sandpaper, a wooden bar with a thread, cargo from the mechanics of 100 g (2 pcs.), Supporting abstracts.

Preparation for lesson:

• each student on the table is issued a sheet of reference abstract, equipment, sheets with test tasks;
• on the demonstration screen or on a large sheet of Watman, you need to prepare a sheet of reference abstract.

Lesson plan

	Types and forms of activity
1. Organizational moment	Greeting
2. Motivational principle of lesson	Setting an educational problem
3. Studying a new material	Story - Conversation, Frontal Experiment, Filling the Support Abstract
4. Stage of generalization, systematization of knowledge and fixing a new material	Performing test tasks, practical work in groups
5. Summing up, homework	Records on the board and in diary, reflection

During the classes

I. Organizational moment.

II. Motivational principle.

Teacher: Hello Guys, Today, we will continue to travel with you through the Kingdom of Force.

Close to the clouds
Listen to birds
Try to springs -
Nothing to repeat.
For a moment MIG, in an hour hour
Flip in amazement
Everything will be all right - not so
One moment
On the road we will take baggage:
Tutorial, pen, pencil,
Notebook and sacred knowledge.

But before you go on a journey through the kingdom of forces, let's remember the countries of what time we have already visited? (Gravity strength, strength of elasticity, body weight)

We are opening the way to the kingdom of forces, now we will find out, on the journey for which country we will go today. And we will take your trip by car. Sitty and drove.

(The teacher on the demonstration table leads to the movement of the toy car)

Teacher: What bodies interact when moving the car? What is the result of interaction tel? What happened to the speed of the car? Why did the car stopped? (the strength of friction is valid) I invite you on a trip to the country of friction!

III. So, we begin our journey from visiting the scientific center of the country "Friction force". During the journey, we will conduct travel notes, i.e. the support abstract (students are recorded in the reference summary of the lesson).

Support

Teacher: I am a master of accurate sciences welcome you to the Scientific Center. Here you have to get acquainted with the phenomenon of friction, find out what types of friction live in this country, to determine the point of the application and the direction of this force, to experimentally establish, from which the friction force depends and why does it occur?

Question: Find out in which direction is our car moving? Do you think the strength of friction helps the movement of the car, or prevents? (interfere

If physicists decided to issue all the forces of the passport, then three graphs would necessarily be in this document: a module. Invention. Point of application. We define which way the strength of the friction is always directed? (in the opposite side of the body movement) Determine the point of the friction force application (specify the point of application and the direction of friction force in the reference abstract).

We introduce the definition of friction force:The force arising from the movement of one body along the surface of another attached to the moving body and directed against the movement is called the force of friction.

Teacher: Residents of this hospitable country are waiting for us. Get acquainted with them closer. We learn what types of friction exist.

Demonstration experiment(Book and handle, teacher demonstrates the power of friction of slip, rolling and peace).

Teacher: So, we met the family of friction force. It is friction rolling, slip and peace (pupils are recorded in the reference abstract). And now I offer to relax in the literary living room. Consider examples of the manifestation of friction forces in nature. In the examples of the examples, determine which friction force acts on the body.

In winter twilight nanny fairy tales
Sasha loved. In the morning in Salazki
Sasha sat down, flew the arrow,
Full happiness, from the mountain ice.

N. A. Nekrasov (Slip friction force)

Along the edge of Vova rides
On his bike
And lucky jam
Everyone for treats. (rolling friction force)

Here and winter! Fresh frost
On the sun sparkling in the snow
Let's go with the goods
According to Rus along and across.
Creep crepes oak poloz.
Lee River, Lee Steppe - No need,
Traces will be laid everywhere!

I. S. Nikitin (Slipping Power)

Although it's hard at her burden,
The cart on the move is light;
Ditch dashing, gray time,
Luck does not get off the irradiation.

A. S. Pushkin (rolling friction force)

Cat for bug
Bug for granddaughter
Grandmother's grandmother
Grandma behind Ditch
Dedka for Rust

Tent - pulled, can't pull it out. (rest friction)

Teacher: Why does the friction force arise? What are the causes of friction force? We will experiment (toy car, sand).

Output: Roughness of surfaces, irregularities (accounting is recorded in ok).

Experiment with two glass plates.

Output: The interaction of substance molecules (accounting is recorded in ok).

Teacher: Power is a physical value. What does it mean? (it can be measured) Now we measure the strength of friction, which acts on the wooden bar.

Front experience: Wooden bar with thread, dynamometer.

The teacher explains the class how to measure the strength of friction. Two forces act on the bar in the horizontal direction. One force is the strength of the elasticity of the spring of the dynamometer, directed towards the movement. The second force is a strength of friction against movement. Since the bar moves evenly, it means that it is equal to zero that is equal. Consequently, these forces are equal to the module and are directed in opposite sides. The dynamometer shows the strength of friction (uch-Xia measure friction force).

IV. Teacher: Let's continue our journey. Look at the creative workshop. I am an experimenter and you too (dress up a robe ). I suggest you to compare the strength of friction of peace, slip and rolling, as well as study the power of friction slip.

Students perform practical work in groups (front experimental tasks in physics: manual for teachers / V.A. Burov, V.I. Sviridov. - M.: Enlightenment, 1981. - 112 c).

Teacher: Guys, and you know that in this mysterious country, the strength of friction is constantly changing. It is reduced, then increase. Let's try to learn more about it. You are invited to solve the witty tasks of Oster.

Task 1. The hooligans of Sidorov and Ivanov sprinkled the rink of sand and are watching with interest as the Tanya Petrov skates. What purpose are Ivanov and Sidorov? (increase in friction force)

Task 2. What did the tricky seventh graders, who do not regret the expensive machinery, generously pour it in the brake of the car director of the school? (reduce the strength of friction, lubrication)

Teacher: Each of you constantly solves everyday tests. So now you have to solve some of the problems that you encounter at home.

Students perform test tasks "Laintish test".

Lowish tests

1 group

• The door of the cabinet in the vanine room began to creak. Vanya smeared loop oil and creak stopped. What phenomenon he used?
• In the campaign, Vanya slipped on wet grass, fell and realized that ....

2 groups

• Vanya saw that Mom could not remove the ring from his finger, and advised her to wash his finger. Mom accepted the Council, and the ring easily starred. What is the basis of Vanino proposal?
• From the window Vanya saw that an ice track was formed in front of the door of their house. Vanya came out and sprinkled with sand. Why did he do that?

3 Group

• Vanya gathered on a hike on a bike. But the pedals were badly spinning, and he smeared them with machine oil. What phenomenon he used?
• When the first snow fell, Dad Vanya began to change the summer car tires on the winter. In winter tires, the tread drawing was deeper, as well as they had spikes. Vanya asked her father, why change the tires from the car?

4 Group

• Vanya gathered to ride with friends skiing. Before walking Vanya advised friends to lubricate skis with a special ointment. What is Vanin Founded by the Council?
• Vanya noticed that in winter the highway sprinkles with a special mixture (sand and salt). He decided to ask his father, what role does this mixture play in the car movement?

Teacher: Recently, Dunno was "the strength of friction" in the country. He left us his notes. Let's look at them. What mistakes allowed Dunno? (codecope, film)

Teacher: Guys I invite you to go to the cinema for watching the movie "Friction Strength".

View the multimedia presentation "Friction force" (attachment 1).

Teacher: We leave the kingdom of forces, but at the exit we are waiting for a test. Take the sheet control sheets and follow the task test.

TEST

1. Sledge roll off the mountain. What kind of friction force acts in Sanki?

P. Power of friction rolling
W. Slip friction force
B. Power of friction rest

2. In the Hollyeditsa, the sidewalks sprinkle with sand. At the same time, the force of friction soles of shoes about ice ....

C. increases
D. does not change
E. decrease

3. How is the friction force direction when the body moves?

A. in motion
P. against movement
N. does not have directions

4. When lubricating rubbing surfaces, friction force ...

I. not changing
E. decrease
W. increases

5. Elektrovoz, moving evenly, pulls the railway composition of 150 kN by force. What is the power of friction?

K. 15 KN
L. 300 KN
H. 150 kN.

Table of answers

Check the answers. Who got the code word "success"?

V. Teacher: Our journey around the country "Friction force" is completed. Summarize (validation).

Reflection: Guys, please analyze the "movement" of your thoughts, feelings, feelings that have had during the lesson. Record them on leaves and hand me out.

Preview:

Friction - the type of interaction of bodies The force arising when contacting the surfaces of the bodies and prevents them with relative movement is called friction force. F Tr.

Causes of friction: roughness of surfaces of contacting bodies Mutual attraction of molecules of contacting bodies

Rain friction force is a force that prevents the body to move the body.

Slip friction force Slip friction force is resistance when sliding one body over the surface of another.

Rolling friction is the power of resistance when rolling one body over the surface of another.

Types of friction force friction peace friction slip friction rolling

Comparison of rolling friction and friction force of sliding pin: with equal loads, rolling friction force is always less than the stroke of the sliding.

Find out what the friction force depends 1 Group 2 Group 3 Group 4 Group 4 Install the dependence of friction force from the surface area to establish the dependence of the friction force from lubrication to establish the dependence of the friction force from the force pressed to the surface to establish friction forces from the roaking surfaces

friction force friction force does not depend: from the area of \u200b\u200bcontacting surfaces.

friction force friction depends: when using lubrication, friction force is less

The friction force depends: from: from strength, pressing the body to the surface. friction force

friction force friction depends: from: from the type of touching surfaces.

The friction force depends on: does not depend on: 1) the kind of rubbing surfaces; 2) forces pressed the body to surface 1) of the air contact area with the surface

"Useful" friction.

"Harmful" friction Ways to reduce friction: replacement of friction of sliding friction rolling. Introduction Lubrication between rubbing surfaces.

Conclusion: The friction force arises between the stagnating surfaces. The friction force depends on the kind of contacting surfaces. The friction force does not depend on the area of \u200b\u200brubbing surfaces. The friction force is reduced by replacing the friction of rolling friction, when lubricating rubbing surfaces.

Table of replies 1 2 3 4 5 y with n e x

Homework. Answer in writing in the notebooks on the question: if the friction force suddenly disappeared, whatever we shouted: "Hurray" or "Karaul"

Thanks for the lesson on the upcoming New Year !!!

The purpose of the lesson to get acquainted with the force of friction; Find out whether the friction force is really stronger than storms, winds and bad weather; experimentally establish the causes of friction force; To find out what kind of friction force exists, as well as find out the positive and negative role of friction strength in a person's life.

Experience 1 Observation of the friction phenomenon on the table is a wooden bar. Push him and watch his movement. Attach the dynamometer to it and pull uniformly. Replace the cylinder bar and do the same. What can you say about body speed? How did she change in experiments?

Experience 2 and 3. Clarification of the causes of friction. We establish 2 reasons for the friction and the presence or absence of similarities between the friction force and the force of elasticity. Experience 2: Take 2 glass plates, press them to each other, and then slide one plate relative to the other. What do you watch? Why are the plates hard to move? Drip pipette on one plate 2-3 water droplets and repeat the experience. Why did it make it even harder to shift the plate? Experience 3: Take 2 pieces of sandpaper and magnifying glass. Consider the surface of these bodies. Fold them and try moving relative to each other. Name 2 causes of friction.

Friction force causes from what the mutual attraction of molecules of contacting surfaces depends the quality of processing of contacting me the surfaces of the substance grease the magnitude of the pressing force of the KI Type of force of the friction force of friction slide friction force rolling force of friction rest roughness comes

I offer questions in poetic form: "Well, friends, tell me why live fish is difficult to keep in your hand? Well, who, guys, knows: why in winter roads are sprinkled to us? Skates with the sands of Egorka somehow climbed onto the slide. Well, now I understand: Shut off Egorch down?

Our attitude towards friction is very controversial. On the one hand, a merciless struggle is conducted with friction: rubbing the surfaces of the machines are carefully polished, simple sliding bearings are replaced by ball or roller, rich lubricant is used, there is a lot of work on creating new ideal lubricants. On the other hand, what would we do if the friction suddenly disappeared? Even when walking friction provides us with a big service - it is so difficult to go on slipping ice. Cars and trains without friction could not touch. And if some kind of body moves, slides to stop it, you need to make an effort.

Do you need to get rid of friction? In the absence of friction, the nails and the screws would slip out of the walls, not one thing could not be held in their hands, no whirlwind would never stop, no sound, but I would have sounded an endless echo, it would be unrepreneurously reflected, for example, from the walls of the room. A visual lesson that convinces us in the great importance of friction gives us every time a holled. We are covered on the street. We turn out to be helpless. Wisdom and life experience every people concludes in sayings. For example: you will not fit, you will not go; The case went like oil; eel in the hands do not hold; What circle is easily rolling; ski slide on the weather; From the hosted thread, the network does not spit; Cleaning rope log houses;

Conclusions: The friction force is the force arising when the single body moves along the surface of the other. Types of friction forces: peace friction force, sliding friction force, rolling friction force. Causes of the appearance of friction force: - intermolecular interaction of surfaces of contacting bodies; -Howness of contacting surfaces of friction force: - aimed to the opposite movement; - has a point of application - a set of points of contact of the surfaces of interacting bodies; - weakly depends on the rate of relative movement of interacting bodies; - dependent on the genus of rubbing surfaces, i.e. from the material and on the quality of surface treatment of interacting bodies; - depends on the strength of normal pressure and grows with its increase; - does not depend (in large limits) from the area of \u200b\u200brubbing surfaces.

Thank you for a good job. And maybe in the distant future, any of you will be a great scientist, and we will all be proud of it. For, as the great M.V. Lomonosov wrote, there can be own platonists and fast intelligence of the Russian Earth to give birth to! Thank you, children, for lesson!

Class: 7

Presentation to the lesson

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Type of lesson: combined.

Type of lesson: Traditional with elements of laboratory work.

Objectives lesson:disclose the concept of friction force, to explain the causes of the friction force, to get acquainted with various types of friction force, find out what factors the friction force depends.

Tasks:

1. Educational:
   • consolidate the existing knowledge on the topic "Forces in Nature";
   • get acquainted with the force of friction;
   • explain the causes of the friction force;
   • continue the formation of the ability to explain the processes in terms of the structure of the substance.
2. Educational:
   • formation of communicative qualities, culture of communication;
   • formation of interest in the subject studied;
   • stimulation of curiosity, activity in class;
   • development of performance.
3. Developing:
   • development of cognitive interest;
   • development of intellectual abilities;
   • development of skills to allocate the main thing in the material studied;
   • development of abilities to summarize the studied facts and concepts.

Forms of work: Frontal, work in small groups, individual.

Means of education:

1. Textbook "Physics 7" A.V. Pryony § 30, 32.
2. Collection of tasks in physics for 7-9 classes, A.V. Pryskin, Chapter 15.
3. Distribution material (test sheets, practical tasks).
4. Dynamometers.
5. Wooden bars.
6. Strips of different types of surfaces.
7. Presentation "Friction force".
8. A computer.
9. Illustrations on the topic.

Lesson plan:

1. Organizing time.
2. Repetition of the material studied.
   1. Testing.
   2. Check test.
3. Definition of the lesson.
   1. The power of friction in life and in nature.
   2. Record the topic of the lesson in the notebook.
   3. Setting the goals and objectives of the lesson.
4. Study of a new topic:
   1. Causes of friction force.
   2. Work in small groups to clarify the factors on which the force of friction depends.
   3. Reports of groups of their work.
      1. The dependence of friction force on the type of contacting surfaces.
      2. The dependence of the friction force from the force presses the body to the surface.
      3. The difference between the force of friction of sliding and the strength of rolling friction.
      4. The friction force does not depend on the area of \u200b\u200bcontacting surfaces.
5. Fastening the material studied.
6. Summarizing.
7. Homework.

During the classes

Stage number	Work teacher.	Work of students	Entries in notebook	Used slides, benefits, equipment, literature	Time
1.	Greeting.				1 min.
2.	Draws the attention of students to the handouts to the test, reminds the rules for filling them.	Fill out the dispensing sheets to the test. Attachment 1		Disposal sheets.	1 min.
2.1.	Reads the test questions, if necessary, comments on them. Collects dispensing sheets.	Answer test questions. Roll down handpers.		Slides 2-7	5 minutes.
2.2.	Requests the student to comment on their answer, and then calls the correct answer and explains it if necessary.	Once again, they think about the answers, the disciples mentioned by the teacher comment on their answers.		Slides 8-14.	5 minutes.
3.	Requests the forces that have been studied at previous lessons. It suggests that the lesson will talk about another force.	They remember what time they have already studied. Gravity strength, strength of elasticity, body weight.			2 minutes.
3.1.	Shows the slides on the screen, demonstrating the value of friction strength in nature and life. Requests students to name the strength of which is in question.	Consider slides, draw conclusions, call strength. (As experience shows in the title, they are not mistaken).		Slides 15-16.	2 minutes.
3.2.	The topic "Power of friction" dictates and writes it on the board.	Record the topic of the lesson in the notebook.	Topic: "Friction force" -	Slide 17.	1 min.
3.3.	Gives the definition of friction strength and asks to write it to the notebook. Defines the purpose and objectives of the lesson. Cleaned sheets with group tasks.	Wear entries in the notebook. Carefully listen to the teachers.	- This is the force arising from the movement of one body along the surface of the other attached to the moving body and preventing the movement.	Slide 17.	3 min.
4.	Requests the disciples to help him explain the new material.	Prepare to help.
4.1.	Relying on life experience shows that one of the reasons - the irregularities of surfaces demonstrates that in this case the friction force can be reduced using lubricant. Other - the interaction forces of molecules. Dictates the basic positions in the notebook.	They remember where in life they came across the force of friction, lead records in the notebook.	Causes of friction force 1. The irregularities of contacting surfaces. (With the help of grease irregularities can be reduced).	Slides 18, 19, 20	5 minutes.
			2. Mutual attraction of molecules of contacting bodies	Slide 21.
4.2.	It suggests that friction force depends on a number of factors and asks students to find out what these factors and how they affect the force of friction. Explains that the dynamometer shows the force of elasticity (thrust force) and it will be equal to the power of friction only in the case of a uniform movement of the bar.	Pupils are divided into groups (division into groups and lists of groups was presented to the teacher before lesson). Each group performs tasks that are written on handouts. Appendix 2. The results of their experiments they are recorded on special sheets - tables.		Slide 22. Disposal sheets. Equipment: Bars, loads, dynamometers, removable wheels, various types of surfaces.	10 min.
4.3.	Announces the completion of practical work, asks the groups to get ready to voice the results.	Preparing to report on the work done, choose a student who will go to the blackboard. (It is best to discuss it even before the lesson).	The friction force depends on:		1 min.
4.3.1.	Heads the answer, if necessary, asks leading questions. Complements the student's response by examples from life ( corrugated sole of winter shoes, studded sneakers, winter tires in cars and bicycles).	It turns out that the friction force depends on the type of contacting surfaces, make the necessary entries in the notebook.	1. The type of touching surfaces.	Slide 23.	2 minutes.
4.3.2.	(The wheels of trams and trains, as well as rails have a smooth surface, but the friction force is large due to the high weight of trams and trains).	It turns out that the friction force depends on the strength pressed the body to the surface, make the necessary records in the notebook.	2. Forces pressed the body to the surface.	Slides 24, 25	2 minutes.
4.3.3.	Heads the answer, if necessary, asks leading questions. Complements the answer examples from life (The use of volokus in some tribes, the invention of the wheel, dragging in antiquity of ships with a case with the use of logs, the use of special horizontal baskets from twisted rods during the construction of Stonehenge, the use of bearings to reduce friction force).	It turns out that with equal loads, the sliding friction force is always more rolling friction force, make the necessary entries in the notebook.	3. With equal loads, the rolling friction force is always greater than the stroke of the slip.	Slides 26, 27, 28, 29, 30	2 minutes.
4.3.4.	Heads the answer, if necessary, asks leading questions. Complements the answer examples from life (The ancient Egyptians who have erected unprecedented pyramid from thoroughly treated rectangular blocks, probably knew that the resistance when dragging such blocks does not depend on whether they lie to the pier, rest on the side face or stand "on the pop.". For the first time, this phenomenon was interested in French The scientist Gilo Amonton at the end of the 18th century (1699) his work of the century later continued Charles Pendant and now the law on the independence of the friction force from the surface area wears the name of the Amonton Law - Coulomb.)	It turns out that the friction force does not depend on the area of \u200b\u200bcontacting surfaces.	The friction force does not depend on the area of \u200b\u200bcontacting surfaces.	Slides 31.	2 minutes.
5.	Questions:	Answers on questions.		Slide 32.	3 min.
	1. What is the force called friction force?	this is the force arising when the single body is moving along the surface of the other attached to the moving body and preventing the movement.
	2. What is the cause of friction force?	1. The irregularities of contacting surfaces. 2. Mutual attraction of molecules of contacting bodies.
	3. How can I reduce the power of friction?	Lubricate in contact with surfaces or replace the force of friction of rolling friction force.
	4. From what factors the friction force depends?	1. From the type of touching surfaces 2. From force pressering the body to the surface 3. With equal loads, the sliding friction force is always greater than the rolling friction force.
	5. From what factors does the friction force do not depend?	From the area of \u200b\u200bcontacting surfaces.
6.	Determining the value of friction force in life: What would happen if the friction force disappeared? Comments on the performance of the lesson tasks, estimates, thanks to distinguished students.	If there were no friction, we could not walk on the ground (remember how the legs slide on the ice), it would not be possible to ride a bike, a car, a motorcycle (wheels would be ruined in place), we would have nothing to wear (tissue threads keep friction forces). If there were no friction, all the furniture in the room would have gotten up in one corner, plates, glasses and saucers would sculpted from the table, nails and screws would not keep in the wall, none things could be kept in hand, etc. etc. This can be added that if there were no friction, it is not known how civilization will go on Earth, because our ancestors mined friction fire.		Slide 33.	2 minutes.
7.	Homework, necessary comments.	Recording homework in diaries. Tutorial Pereshkin A.V. - § 30, 32 Collection of tasks Pryskin A.V. - chapter 15.	§ 30, 32 Chapter 15.	Slide 34.	1 min.

Used Books:

1. Pryrickin A.V. Textbook "Physics 7".
2. Pryrickin A.V. "Collection of tasks in physics 7-9 classes", Moscow, "Exam", 2006.
3. V.A. Orlov "Thematic tests in physics 7-8 classes", Moscow, "Verbum - M", 2001.
4. G.N. Stepanova, A.P. Stepanov "Collection of questions and tasks in physics 5-9 classes", St. Petersburg, "Valeria SPD", 2001.
5. IN AND. Grigoriev, G.Ya. Myakyshev "Forces in Nature", Moscow, "Science", 1988.
6. kak-i-pochemu.ru.

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Purpose: consolidate the knowledge gained in nature; introduce students with friction force; experimentally find out what friction force depends on; consider the types of "dry" friction; Compare rolling friction, slip, rest; Teach students to determine the type of friction; Introduce the calculated formula for finding friction force (slide 2).

Required technical equipment: Interactive board, computer, projector.

Software: PowerPoint, video player, presentation.

Registration: The board shows the topic of the lesson and tasks to actualize knowledge. The printed halves are written on the folding halves (or printed) about the strength of friction.

Equipment: Wooden bar with grains of different areas, but the same surface roughness; Set of loads of 100 g; Wooden, badly ground board; Dynamometer, rollers (2 cylindrical stem, for example 2 pencils).

Explanatory note on the use of the presentation. (Attachment 1)

During the classes

1. Organizational moment. Hello. Today, at the lesson, we will try to find out the meaning of some Russian sayings from the point of view of physics. (Slide 3). For this, we will confirm or refute the possibility of the described events. But first remember what we studied in previous lessons and what you need today.

2. Actualization of knowledge.

BUT) One student works for an interactive boards: Portray body weight, strength of elasticity and gravity. (The teacher pays attention to the point of the application and the direction of force). (Slides 4, 5)

B) At the board, the teacher prepares the tasks. While the student works at the interactive board, the entire class works independently in notebooks, the answers will be discussed when checking using the presentation.(Slide 6)

1. Where is the strength of gravity more? Where is more weight?

2. Where is the force of elasticity more (k 1 \u003d k 2)? What can be said about the strength of gravity if the bars rest? (Slide 7)

3. Where is the rigidity greater than (M 1 \u003d m 2)? What can be said about the strength of gravity if the bars rest? (Slide 8)

4. Determine and designate the resultant forces. Where in this case will the body move? And if you get rid of the strength marked with black, how will the body move? (Slide 9)

C) Two student (sitting at one desk) get a task and equipment: "Build a graph of body weight dependence on the mass. Equipment: Dynamometer, Truck Set " Students represent the results of the work of the class and conclude after discussion of all issues.

The teacher watches how students perform work and provides the necessary assistance. After 5-7 minutes, the check is organized. Focus on the key points that should have been noted by students when performing tasks.

3. New material

In previous lessons, we have repeatedly affected the question that if there are no other bodies on the body or the effect of these bodies is compensated, the body either rests or moves straight and evenly (slide 10). The physical value that characterizes the effect of bodies on each other is called force. Let's carry out an experiment: dynamize a dynamometer of a bar with weights so that the movement is uniform. Why is it becoming possible? That's right, the force of thrust in this case is compensated for some more force, we have not yet known yet? (Slide 11). Let's try to find out what it is for the power where it occurs where it is directed and depends on.

A teacher with assistants issues equipment (see above) to each desk.

Spend the same experiment yourself and think: where is the force unknown to us?

This force is called friction force. The FTR is indicated, is measured in N. In connection with which it occurs? In connection with the contact of the bar and parties, it means that there arises in the place of contact of the two bodies. The causes of the friction force are two (slide 12). When one body slides over the surface of another, irregularities cling to each other, which creates some power, delaying movement. But if you take 2 well-polished items, for example, two glasses, the friction force is also high, since in this case there are mutual attraction forces between molecules of contacting bodies, which are the cause of friction.

What do you think this power can depend on? Check your guesses. Possible assumptions. (Slide 13, 14)

(It is better to organize the work by groups - each group checks one hypothesis and voiced, comments the result)

1. From speed (independent).

2. From the mass transferred.

The more P, the more FTR.

4. From surface roughness, etc.

A teacher helps to simulate the experiment of students in such a way as to check all the suggested assumptions. After that, all conclusions are recorded.

In notebooks write the FTR. (Slide 15)

1. Directed to the side opposite to movement.
2. Occurs in the place of contact of two bodies
3. Depends: on the weight (mass) of the body and roughness of the surface.

So The FTR is calculated by the formula (slide 16): FTR \u003d μN, where μ is a friction coefficient depending on the kind of rubber surfaces, N is the reaction force of the support, i.e. The strength of elasticity arising in the support under the influence of body weight.

Let the definition of the FTR - it is the force arising from the interaction of the surface of one body with the surface of another when the bodies are fixed, or move relative to each other.

And now put under the bar with weights of the rollers and measure the friction force. Compare it with the testimony that you have completed for the same weight in the previous experiment. What conclusion can be done? True, this friction force is less. Now put a bar with weights on a rough plane and try to move it. What is observed? The force first increases greatly, and when the bar comes in motion - it becomes equal to the force of friction obtained by sliding. Those. In nature, there are three kinds of "dry" friction: the strength of friction of sliding, rolling friction force and the strength of friction of rest.

Arrange the signs between the FTR. Issue _____ FTR. Pokoy. (Slide 17)

4. Fastening

(Slide 18) Arrange the type of friction force for each depicted situation. Give your examples of each type of friction force.

How can I increase and reduce friction force?

Explain the meaning of the sayings presented on the board. Do they have a physical meaning? (Slide 19)

Additionally: Give examples of manifestation of friction force.

Is there a benefit from the friction force? What?

What harm brings the power of friction? Is it possible to deal with it? How?

Homework: §30, 31, tasks 1 and 2, home experiment, get acquainted with an additional material. (Appendix 2). ( Issued either in printed or in electronic form). (Slide 20).

Bibliography

1. PRIRRYKIN A.V. Physics. 7 CL: student. For general education. Institutions / A.V. Pereyshkin. - 12th ed., - M.: Drop, 2008.

2. Volkov V.A., Polyansky S.E. Pounding development in physics: grade 7. - 2nd edition. - M.: Vako, 2009

The peculiarity of the pedagogical system of multi-level continuous creative education NFTM-TRIZ consisting in the fact that the student from the learning object becomes the subject of creativity, and the educational material (knowledge) from the subject of assimilation becomes a means of achieving some creative goal, until recently, it was my dream as a teacher. Today, slowly, but right, the dream becomes reality.

Make an element of creativity in the lesson, bring bridges between physics and lyrics, tie boring physical laws with accumulated life experiences, has always been one of the important components of my pedagogical activities. But one thing is "boiling" in your own boiler, and another, when at all levels of education goes continuous Formation of creative thinking and the development of creative abilities of students, search for highly efficient creative solutions.

The German teacher A. Disterweg said: "The student takes place within a few years the road at which humanity used millennium. However, it should be guided by the goal not blindfolded, but in vain: he must perceive the truth not as a ready-made result, but should open it. The teacher must lead this expedition of discoveries, therefore, also be present not only as a simple viewer. But the student must strain his strength, nothing should be delivered to him. It is only given to someone who seeks. " How it is right and in unison with the requirements of the new educational standard it is said!

I, with some soulful trepid, anticipating a meeting with sections, ready to independently set goals, focusing in a situation, creatively thinking, act ...

But then the teacher will have to adopt the principle of hippocrat "not harm" as: helping the child to develop the personality, gain spiritual and moral experience and social competence.

In the Federal State Educational Standard of the Basic General Education (GEF LLC), in the requirements for natural science subjects, there are, in particular,

Mastering the skills to formulate hypotheses, design, conduct experiments, evaluate the results obtained;

Mastering the ability to compare experimental and theoretical knowledge with objective realities of life.

About how, applying the block structure of a twined creative lesson, these requirements can be implemented using the techniques and methods of NFTM-TRIZ, I will show the example of the lesson of physics in the 7th grade "friction force. Friction types. Friction in nature and machinery. "

The principle of work is the education of the person through creativity.

The task is to create pedagogical conditions for identifying creative abilities and their development.

The epigraph to the lesson took two aphorism (although they reflect, in my opinion, the whole line of development of creative thinking and abilities, so they can take the honorary place in the office of the Cabinet):

Man born for thinking and action.

Aphorism of the ancient Greeks and Romans

Abilities, like muscles, grow in training.

Domestic geologist and geographer V. A. Obruchev (1863-1956)

Block 1.. Motivation (5 min). For the development of curious student at the beginning of the lesson - experience.

On the demonstration table there are two deep plates filled to edges with water. The teacher invites two assistants to the board and offers to participate in the experiment. It gives one student a tennis ball, the other - the same rubber. Task: make the balls rotate in water as quickly as possible.

What do you observe?

Which ball is spinning in the water faster?

What do you think the tennis ball is spinning faster than rubber?

The output to which we arrive after a comprehensive analysis of the task: the tennis ball rotates faster than rubber, because Its surface causes less friction with water.

The friction is the interaction that occurs when contacting one body with another and preventing relative movement. And the force characterizing this interaction is the friction force. Today at the lesson we will reveal all the secrets of this amazing phenomenon - friction. Ready? Then for business!

Block 2. Substantive part (30 min)

In children on the tables: the coil from under the thread; gum loop; Smooth buttice, two matches, glue. The teacher suggests, using the set of these tools, create a moving structure.

Work in groups (the teacher controls the process of search and communicative activity), a demonstration of what happened and the story about how they acted:

What ideas were born?

Why stopped on this?

How did it embodied?

What problems faced?

How did they solve them? Did everyone managed?

How was the team working?

Sample possible design:

Fig. one

1 - coil from under the thread;

2 - loop of gum;

3 - smooth button;

4 - chip match, which has been done in the loop (it is better to glue it to the coil);

5 - match.

All groups have worked in inventors, the result of the work of creative thought is a moving structure. The goal is achieved. Not a small role in this played the coherence of the team, the ability to listen to each other, formulate and argue their opinion and correctly upholding its position. But all of you note that the speed of your typewriter is not so high as you want.

In order to understand how to make the resulting design, it is necessary to deal with what prevents it from moving the way that we want.

The search will be conducted in 3 directions: the cause of friction, types of friction, the factors determining it. Records open on the chalkboard:

Reasons for friction: Friction types: friction depends on:

I have no doubt that there are already ideas. There is a desire to state your point of view, - Let's listen with pleasure.

We work in the Scenario Replacement Group: Idea → Experience → Conclusion.

Each group receives equipment for experiments: Wooden bar with crochet, loads, dynamometer, wooden board 50 × 10 cm, boards of the same size, upholstered linoleum, rubber, round pencils. And on an interactive blackboard - tips in the form of pictures:

Fig. 2 Fig. 3 Fig. four

Fig. 5 Fig. 6 Fig. 7.

Find the pictures on which friction is found. Explain your point of view.

Pay attention to fig. 3, 4, 5. What about them in common, and how are they different? (General - friction. But at the same time, the hockey player is sliding, the cart - rolls, and piano - stands on the spot).

In nature and technique there are three types of friction: peace, slip, rolling (+ recording on the board). Try to give them definitions. Find them in other pictures.

What causes the occurrence of the friction force? How do you think?

Put the bar with a cargo on a wooden board. Attach the dynamometer to it and, airing with the force parallel to the board, move the load evenly. Record the dynamometer readings. What power are we measured? (The force of thrust equal to the power of slip friction).

Repeat experience on linoleum and rubber. Make conclusions
(1) One of the reasons for friction is the irregularities of contacting surfaces that are cling to each other when moving; 2) friction force depends on the material of contacting surfaces) → records on the board.

Add cargo to the bar. Repeat the experiment. Formulate output. (The friction force is directly proportional to the strength of normal pressure) → Record on the board.

Put the bar with bathers on pencils. Experiment. Output.

Guys, what do you know about lubrication? What is its role? What pictures is it present on?

At one time, the great Italian artist and the scientist Leonardo da Vinci, surprising the surrounding surroundings, spent strange experiments: he dragged the rope on the floor to the whole length, then collecting her rings. He studied: Does the stroke power dependent on the area of \u200b\u200bcontacting bodies?

Before we find out, what conclusion came Leonardo da Vinci, let's try to answer this question too. But here is the principle: we have no ropes. How to be? Is it possible to do with undergrades? We find a way out of the position in Bruke, in which the faces of the faces are different. By comparing the force of friction of sliding at three positions of the bar, we come to the conclusion that the stroke force of the slip in all cases turned out to be the same, that is, it does not depend on the area of \u200b\u200bcontacting tel. And what about Leonardo? (I read the answer). And here she is the joy of knowledge!

And now I suggest you for the purpose of the self-analysis of the material studied, fill out 2 tables, making an oral story on the resulting records. In the case of difficulties, turn to 30 and 31 textbook paragraphs.

Table 1

Studied physical phenomenon

table 2

Forces with whom I met

You work first on your own, then in groups are discussed, adjusted, "polished" records.

But it turns out that one problem arose in all: the formulas for calculating the friction force in the textbook there.

Guys, you already know that the gripging force depends on the weight of the body and the material of contacting surfaces. The value that characterizes the dependence of the friction force on the material of contacting surfaces, their processing quality is called the coefficient of slip friction μ. Thus, the formula for calculating the friction force of the slip: F \u200b\u200bTr \u003d μmg.

I think that now you are ready to make your design at high speed, bringing to perfection. This will be your homework. In the next lesson - the competition of your "machines". Winners are waiting for high marks. And now…

Block 3. Psychological unloading (5 min)

The boys draw are divided into two teams, competing in tugging the rope. Girls - fans. They will also be explained, what could be the cause of victory or a team loss. With what kind of friction and where collided in this contest? Did it speak in the role of an assistant or interference? What would you suggest to increase the friction soles about the floor? hands about rope?

Block 4. Puzzle (10 min)

Tell me, guys who do you like to go skiing? My class sometimes spend the weekend for this wonderful class! True, memories of our first campaign cause us mixed feelings, because We were pretty pretty: Ski all the time "sought" to roll back, incredible efforts should be climbing on the very small hug.

What do you think it was wrong with us? - Lubrication! And why? It would seem that ski slides requires a decrease in friction and that's it. No, not all. When combating skiing (classic style), two types of friction appear. What kind? One useful, and it should be increased, another harmful, and it needs to be reduced. So, increase and reduce at the same time! It is clear how difficult it is to pick up such a face that, as they say, "and the sheep were intact, and wolves are full." For every weather, it is its own - this hard-tissue line. Error - and skiing will either slide badly, or keep bad when repulsion (return). On this occasion, Finns have a proverb "Ski slide on the weather."

In proverbs - short sayings, teachings - national history, worldview, life of people appear. But all this is inextricably linked with physics. Today I offer you several proverbs that are related to our topic (distributed by the draw groups). Your task: read the proverb and answer the questions:

1. What is her physical meaning?
2. Is the proverb true from the point of view of physics?
3. What is her everyday sense?

Proverbs:

It went like oil (russian).

Ski slide on the weather (Finnish).

From the hosted thread it is difficult to weave the network (Korean).

Thick in your hands will not hold (french).

Not fit - you will not go (french).

The watermelon crust bypassed, and on coconut slipped (Vietnamese).

KOSI KOS, while dew; Dew Down, and we are home (Russian).

Block 5. Intellectual warm-up (15 min)

Today you, my young physicists, I will tell you the Fairy Tale of "Republic" about the strength of friction of rest, the mechanism of its occurrence, the magnitude and direction. Listen carefully, since at the end you have to answer 10 questions easier than the "paired turnip".

So listen.

Put grandfather repka. Grow-sorted repka rose, heavy, heavy, it rushed in all directions, the soil pledged. That is why very tight contact with her tuber with the soil turned out, in all the smallest cracks and protrusions, the earth penetrated. I went grandfather to tear. Pulls, pulls - can't pull out. He lacks strength: Refiliates, the irregularities and protrusions behind the land clings, opposes its movement. In places, the gap between repka and the soil sections of the order of the radius of the molecular forces turns out. There, the adhesion of the soil particles with repka occurs, the movement of repka relative to the earth it hinders.

Called grandfather grandmother. Grandma behind the grandfather, Dage for the Republic, pull-pull - to pull out can not be: strong thickened-rounded root in the ground is kept. The force of gravity to the ground presses. No, and together do not cope.

I called grandmother granddaughter. Granddaughter for the grandmother, grandmother's grandfather, Dedka for Rack, pull-pull - it cannot be pulled out: still their total thrust force is less than the ultimate force, which on the surface of contacting the turnip of the earth arises. She is called friction friction. Caused by external force, but always against external force and sent. This force is ambiguous - Multicolia. In wide limits, it can change: from zero to a certain maximum value ... it can be seen, it has not come to this maximum value.

I called the granddaughter of the bug. Bug four paws in the ground rested. Between the paws and the earth, too, the force of friction of peace occurs. It helps this power bug just like grandfather, grandmother and granddaughter. Do not be this strength, they would not be able to resume, they would slide on the ground, slipped. Bug for granddaughter, granddaughter for the grandmother, grandmother for the grandfather, Dedka for Rack, pull-pull - can't pull out. And in fact, the micron has already moved a repka. The magnitude of these micro movements is proportional to the applied strength and the properties of the soil itself depends. And the sticking of ribs from the ground and the elastic deformation of the shift of the soil and micro protrusions of the reprection itself while trying to stretch it into an increase in the force of the soil elasticity. And this elastic force of the soil, essentially, is the strength of rest friction. Does not give it to pull the rep.

Cook a bug cat. A cat for a bug, a bug behind his granddaughter, granddaughter for the grandmother, grandmother for the dog, pull-pull - can't pull out: the smallest thing, but still less external force turned out to be the maximum possible value of peace friction.

Call a cat mouse. The mouse for the cat, a cat for a bug, a bug for granddaughter, granddaughter for the grandmother, grandmother for the grandfather, pull-pull - pulled out a rep.

Just do not think that the little mouse turned out to be stronger! How much are the strength of a small mouse! But her little strength to the overall strength of the thrust was added, and now the resulting force even exceeded a slightly maximum value of the quantity of peace friction: more stroke forces has become. There were irreversible relative movements. "Live chain" - from the grandfather to the mouse - the river stretched out, and herself ... fell! More attached power than the power of friction of spraying repka about the ground turned out to be. Here, in the direction of the greater power, everyone fell. But this ... already another fairy tale.

And now the promised questions, it is easier for "paired turnips":

Block 6.. Substantive part (15 min)

A little more and about the strength of friction you will know everything.

Independent work with a tutorial: explore § 32, structure text (scheme, table, etc.), to discuss in the group and the most successful option to submit to all class by protecting it. The work will be evaluated according to the following criteria: an interesting form of submission, the competence of the defender (clear, understandable expressions, the ability to interest the audience, argued to answer the questions asked if they arise), supporting the group. In the presentation of the result, there should be answers to three questions: "Why do you?", "What do you do?" And "How do you do?"

Block 7.. Computer Intelligent Support (10 min)

The cartoon video "Bremen Musicians" (ride, sing "There is nothing better in the world than to wander to friends in Bella Light").

Fig. 8 Fig. nine

Find all that is related to our topic, argue your choice. But it is necessary to introduce this to the "eyes" of physics. One starts the story, the relay takes the second, then the third, etc., if necessary, repeat the cartoon, stopping at the request of the answer.

Block 8. Summary (5 min)

"Make your own" photo "lesson or work"

Imagine that each of you is a photographer, and you need to make some pictures of "Stop-frames" from the lesson or the case you just did. A snapshot can be colored or black and white. Colored stop frame reflects something liked that brought the joy from what he saw, read, performed, designed, etc. Black and white "Stop Frame" should show what you did not like it, failed, disappeared.

Each depicts how he makes his picture: Holds a camera in his hands, descends the shutter and loudly comments on the frame, explaining why I liked something or did not like it. Then the camera must be transferred to another student.

The last few "still frames" makes a teacher.

1. Zinovkin M. M., Utles V. V. Structure of a creative lesson for the development of the creative identity of students in the Pedagogical system of the NTFM-TRIZ // Socio-anthropological problems of the information society. Issue 1. - Concept. - 2013. - Art 64054. - URL: http://e-koncept.ru/teleconf/64054.html
2. Federal State Educational Standard of Basic General Education. - URL: http: //minobrushuki.rf]
3. Experience "friction" - magic lessons. - URL: http://lmagic.info/friction.html
4. Balashov M. M. About Nature: KN. For students of 7 cl. - M.: Enlightenment. 1991. -64 C.: Il.
5. Teaching physics, educational student. - KN. 2. - The development of thinking: general performances, learning to mention operations / Sost. and ed. E. M. Braverman. Manual for teachers and methodists. - M.: Association of Physics Teachers. 2005. - 272 p.; Il. - (identity-oriented training.)
6. Class! Naya Physics. - URL: http://class-fizika.narod.ru/
7. Pryrickin A. V. Physics. 7 CL: student. For general education. institutions. - 8th ed., Stereotype. - M.: Drop, 2004. - 192 p.: Il.
8. Tikhomirova S. A. Physics in proverbs, riddles and fairy tales. - M.: School press, 2002. - 128 p. - (library of the magazine "Physics in School"; Issue 22)
9. Physics lesson in modern school: work. Search for teachers: KN. For Teacher / Sost. E. M. Braverman; Ed. V. G. Romumbovsky. - M.: Enlightenment, 1993. - 288 S.
10. Teaching physics, educational student. Kn. 1. Approaches, components, lessons, tasks / Sost. and ed. EM. Braverman: allowance for teachers and methodologists. - M.: Association of Physics Teachers. 2003. - 400 p.; Il. - (identity-oriented training.)