Presentation on the topic of ways to reduce pressure. Pressure. Ways to reduce and increase pressure. wide car tires

What determines the effect of a force on a body? Force of elasticity F control; Gravity F heavy; Body weight R; Friction force Ftr. What types of forces do you know? What is strength? What is strength? Force is a measure of the interaction of bodies. The result of the action of a force on a body depends on its module, direction, and point of application.

Elastic force arise during deformation; occur during deformation; at the same time at two bodies; at the same time at two bodies; perpendicular to the surface; perpendicular to the surface; opposite to displacement; opposite to displacement; for small deformations, Hooke's law is fulfilled F control = -k x for small deformations, Hooke's law is fulfilled F control = -k x

Gravity The force with which the Earth pulls a body towards itself. The force with which the Earth pulls a body towards itself. The formula for finding the force of gravity The formula for finding the force of gravity Fт =mg. Ft \u003d mg. Directed along the radius to the center of the Earth; Directed along the radius to the center of the Earth; related to gravitational forces related to gravitational forces

The pressure unit is taken as the pressure that produces a force of 1 N acting on a surface of 1 m 2 perpendicular to this surface 1 Pa1 N M2M2 Pressure unit Blaise Pascal () French mathematician, physicist, writer and philosopher.

Derived units: 1 kPa = 1000 Pa; 1 kPa = 1000 Pa; 1 MPa = Pa; 1 MPa = Pa; 1 hPa = 100 Pa; 1 hPa = 100 Pa; 1 Pa = 0.001 kPa; 1 Pa = 0.001 kPa; 1 Pa = 0.01 hPa; 1 Pa = 0.01 hPa; 1 Pa = 0, MPa. 1 Pa = 0, MPa.

Decreasing pressure Increasing pressure Building foundation Aircraft landing gear Wide car tires Caterpillars of all-terrain vehicles, tractors Skis Washers for nuts Sleepers for rails Ax Knife Nails, buttons Needles Teeth, claws, beaks of animals Thorns, thorns of plants Wasp sting

3. The pressure of the body on the surface depends ... A. on the modulus of force and the area of \u200b\u200bthe surface perpendicular to which it acts; B. from the modulus of force and does not depend on the surface area on which the force acts; V. surface area, perpendicular to which the force acts. 4. Express in Pa the pressure of 10 kPa? A.10000Pa. B.100Pa. V.1000Pa. 5. A value equal to the ratio of the force acting perpendicular to the surface to the area of this surface is called ... A. pressure force. B. pressure. B. body weight.

Class: 7

Presentation for the lesson

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Each slide appears on the ID screen when clicked.

Each slide element also appears on click as needed.

Students at the blackboard work with slides 5 and 17 (each picture appears in the course of the explanation and the student's response by clicking)

The task “to prepare a historical note about Blaise Pascal” was assigned to the students in advance.

The use of the presentation improves the visibility of the studied material, which contributes to the development of cognitive interest in the subject.

The purpose of the lesson:

Educational: To form general ideas about pressure, pressure force, its units and ways of changing pressure;
Educational: development of experimental skills, logical thinking, substantiation of one's statements, development of group work skills, justify the need to increase or decrease pressure;
Educational: the formation of skills for independent work, the development of a sense of cooperation in the process of joint implementation of the educational task.

Equipment: multimedia projector, computer, presentation.

Lesson type: combined.

During the classes

I. Organizational moment.

(slide 1, 2)

II. Repetition of the studied material.

1. Teacher:

“The elephant went out onto the forest path,
He stepped on the ant's foot.
And very politely he said to the ant:
"You can step on mine too." (slide 3)

Questions for students:

“Will the end result be the same?”
What determines the action of one body on another? (slide 4)
Answer: by force.
What determines the force applied to the body?
Answer: from module, direction and application point.
What happens to a body when a force acts on it?
Answer: the body can change its speed or deform.

The student goes to the interactive whiteboard (ID) and shows that the result of the force (deformation of the body) depends on the magnitude of the force. (slide 5)

Tell me, the result of the action of a force depends only on its magnitude, point of application and direction?

(students discuss slide pictures 6, 7 and draw a conclusion)

Students' conclusion:

Also on the surface area, perpendicular to which it acts.

III. Learning new material.

(slide 8)

Teacher:

1. The physical quantity characterizing the action of a force applied perpendicular to the surface on which it acts is called pressure.

Question: What do you need to know to find the pressure?

Answer: force and area.

(The teacher enters the designation "pressure" and, together with the students, writes down the formula for calculating pressure and the unit of measurement for pressure)

2. The student reports a historical background on Blaise Pascal (slide 9)

3. Pressure units used in practice (slide 10):

(independent work of students with subsequent verification)

1 kPa=….
1 µPa=…
1 MPa=…
1 hPa=….
1 MPa=

4. Derivation of formulas for calculating force and surface area (slide 11)

(horizontal line - division, vertical line - multiplication)

5. Physical education (slide 12)

Teacher: Please stand up.

Are you putting pressure on the floor right now?

- Will the pressure change if we: raise our hands, spread them apart?

- Is it possible to increase this pressure?

- And how to reduce the pressure?

6. So, the physical education session showed us that pressure is not a constant value and it can be changed (slide 13)

IV. Consolidation of the studied material

1. Look at the pictures. Formulate the problem and explain (slide 14)

(students independently compose tasks according to the drawings and solve them)

2. Answer the questions (slide 15)

3. Work on ID (slide 17)

Look at the bodies in the pictures. Think about which of them increase the pressure exerted on the support, and which decrease, and put in the appropriate place.

V. Summary of the lesson.

(slide 18)

Questions:

What physical quantity is called pressure?
What you need to know to find pressure; as indicated; formula for calculation; pressure units?
How can pressure be increased or decreased?
In what cases the pressure needs to be increased; decrease?
Match:

Homework: § 33, 34

Bibliography. Electronic publications.

Educational electronic edition "Interactive course of physics for grades 7-11", "Physicon", 2004.
"Open Physics 1.1", LLC "Physicon", 1996-2001, edited by MIPT Professor S.M. Cosell.
“Library of electronic visual aids. Physics grades 7-11”, GU RC EMTO, “Cyril and Methodius”, 2003.
"Physics grade 7", publishing house "Drofa", 2001.

MOU "Secondary school with. Stepnoe"

Lesson learning new material Grade 7

Physics teacher Tsupenko Elena Alexandrovna

CROSSWORD
In previous lessons, we talked a lot about the physical quantity that causes the change in speed. What is the name of this value? This is number 4 in the crossword puzzle. We know that there are several kinds of forces.
№ 8 What is the name of the force with which knowledge attracts all bodies to itself?
What does it depend on? How does it depend?
No. 7 (A demonstrative experiment is being carried out, a load on a spring).
What is the force in a spring called? Why is the load at rest?
№ 3 What is the name of the force acting from the side of the load on the spring? What is body weight?
No. 5 (We are conducting an experiment: a bar, a dynamometer). What force arises when one body moves over the surface of another? What is the cause of friction? What types of friction do you know?
What types of friction do you know?
No. 1 A device is used to measure force. What is it called?
№ 6 What is the name of the unit of force?
№ 2 What characterizes the action of force? One of her characteristics is number 2.
Now let's name the topic of our lesson. Vertically in a crossword.
Open your notebooks and write down the topic of the lesson.

Crassword

study the pressure of solids;
in what units is pressure measured;
find out ways to change pressure in everyday life and technology;
learn ways to increase and decrease pressure;
generalize knowledge about pressure, consolidate the studied material;
test and consolidate the acquired knowledge.

The pressure depends on the value of the force that acts on the surface.

The more force, the more pressure

strength

pressure

square

The unit of pressure is the pressure produced by a force of 1 N acting on a surface of 1 m2. 2 perpendicular to this surface

The unit of pressure is Newton per square meter, called the Pascal.

M 2

DERIVED UNITS:

1 kPa = 1000 Pa;
1 MPa = 1000,000 Pa;
1 hPa = 100 Pa;
1 Pa = 0.001 kPa;
1 Pa = 0.01 hPa;
1 Pa = 0.000001 MPa.

animal claw

INCREASING PRESSURE IN NATURE

Crocodile's teeth

INCREASING PRESSURE IN NATURE

bird beak

INCREASE PRESSURE

Needles in medicine

pressure reduction

Increase in pressure

building foundation

Aircraft landing gear

wide car tires

Caterpillars of all-terrain vehicles, tractors

Skis

Washers for nuts

Sleepers for rails

Axe

Nails, buttons

needles

teeth, claws,

beaks of animals

spikes,

plant spines

wasp sting

APPROXIMATE PRESSURE VALUES, ENCOUNTERED IN APPLIANCES AND HOUSEHOLD

PHYSICAL PAUSE.

Before proceeding with solving problems, we will carry out "Gymnastics for the eyes".
Close your eyes and then open them. Repeat 5 times.
Make circular movements with your eyes: left - up - right - down - right - up - left - down. Repeat 10 times.
Stretch your hand forward. Keep your eyes on the fingernail, slowly bringing it closer to the nose, and then slowly move it back. Repeat 5 times.
Look out the window into the distance for 1 minute.

Examination

1. In what units is pressure measured?
A. N. B. Pa. V. m2.
2. What is ... the area of \u200b\u200bthe support, the ... pressure produced by the same force on this support?
A. more; less. B. more; more. V. less; less.
3. The pressure of the body on the surface depends ...
A. from the modulus of force and the surface area, perpendicular to which it acts;
B. from the modulus of force and does not depend on the surface area on which the force acts;
V. surface area, perpendicular to which the force acts.
4. Express in Pa the pressure of 10 kPa?
A.10000Pa. B.100Pa. V.1000Pa.
5. A value equal to the ratio of the force acting perpendicular to the surface to the area of \u200b\u200bthis surface is called ...
A. pressure force. B. pressure. B. body weight.
6. The machine weighing 12000 N has a support area of 2.5m2. Determine the pressure of the machine on the foundation?
A) 48Pa. B) 25000 Pa. C) 4800 Pa.
7. How will the pressure on the table change if you put it on edge?
A) will not change. B) decrease. B) will increase.
8 A box weighing 960 N exerts a pressure of 5 kPa on the support. What is the area of support of the box?
A) 0.192 m.2 B) 19.2 m.2. C) 1.92 m.2