Short-term plan for conducting an open lesson in physics at 8 "B" according to the program

University of Cambridge physics teacher Kuspakova R.T.

Coming together is the beginning. Sticking together is progress. Working together is success.

Henry Ford.

It is not enough to have a good mind, the main thing is to use it correctly.

Rene Descartes.

04/16/16 Physics subject Class 8 "B"

Lesson topic:

Light. Sources of light. The star is the sun. The law of rectilinear propagation of light. Shade and penumbra. Solar and Lunar eclipses.

Duisembaev B.M. etc. Physics and Astronomy: Textbook for 8 cells. general education school, 2nd ed., revised / B.M. Duisembaev, G.Z. – Almaty; Publishing house "Mektep", 2008.-256 p.; ill.

Goals:

The purpose of the lesson:

to acquaint students with natural and artificial light sources; explain the law of rectilinear propagation of light; explain the nature of solar and lunar eclipses.To encourage students to overcome difficulties in the process of mental activity, to cultivate interest in physics.

Learning outcomes:

Everybody knows what is light, shadow, penumbra, eclipses.Most can applyon practicebasic knowledge of light phenomena.Some are capable analyze the differences in the formation of shadows and penumbra, eclipses.Be able to describe physical phenomena based on knowledge. Be able to formulate complete and competent answers and questions.Learning new concepts, teaching how to work in a group, the ability to listen to opinions, ask questions on the topic.

Key Ideas:

group mutual learning will allow students to get closer, teach the ability to hear and listen to the interlocutor, be more tolerant of each other, increase learning and cognitive motivation, improve the psychological climate in the classroom; the ability to conduct a dialogue will teach you to argue your point of view; activation of students' critical thinking will allow them to solve the problems posed to them, develop research skills based on their own and indirect experience, increase the efficiency of mastering and updating knowledge, which will make it possible to transfer students to self-development mode.

Time

Strategies

Resources

Lesson content

Teacher activities: what will I do?

Activity

students

Org.

moment. (2 minutes)

Greeting, division into 2 groups(according to the inscription on candy wrappers), and representation of the expert council

greet

each other- Cross your arms over your chest (Arabs).
To create a collaborative environment, he uses the "Compliments" strategy.

Compliment the neighbor on the right, and thank the neighbor on the left for something.

Introductory part (10min)

ICT,

group work,

KM,

ODO,

Internet resources.

Textbook

physics grade 8,

physics handbook,posters,

Cell Phones.

Before starting to study a new topic, it is necessary to analyze the results of the test, answer questions that have arisen on the work, and analyze the most common mistakes.I . Learning new material Plan for presenting new material: 1. Light as visible radiation. 2.Natural and artificial light sources. 3.Beam and beam. 4.The law of rectilinear propagation of light. 5.Shade and penumbra. 6.Solar and Lunar eclipses. In a short introductory talk, I will tell students about the importance of light in man's knowledge of the world around him. Thanks to the organ of vision, a person sees the world around him, communicates with the environment, can work and rest. The productivity of labor depends on how objects are illuminated. Without sufficient lighting, plants cannot develop normally. Knowledge of the regularities of light phenomena makes it possible to design various optical devices that are widely used in practical human activities. The best illustration of the significance of light phenomena in human life is a “minute” experiment: invite students to close their eyes for one minute and imagine “life in darkness”!!! What is light? All bodies are made up of atoms (or molecules). But just as there is no sound in a guitar string, so there is no light in an atom. The state of an atom, when its energy is minimal, is called normal (or unexcited). In this state, the atom does not radiate energy. Any other state of an atom with energy other than the minimum is calledexcited. An atom can be in an excited state for 10 3 with. The transition of an atom from an excited state to a normal state is accompanied by the emission of electromagnetic waves.Light is electromagnetic radiation perceived by the eye through visual sensation. Question:-How does the radiation of an iron or boiler differ from the radiation of an electric incandescent lamp?light source are called bodies capable of emitting light. Any luminous body consists of a huge number of "elementary" emitters. Thus, the optical radiation of light sources is a set of radiation from individual atoms and molecules. "Demonstrating to students various light sources (a burning match, a candle, a glowing light bulb), the teacher reports that there arenatural andartificial sources of light. Natural light sources are the Sun, stars, atmospheric charges, as well as luminous objects of the animal and plant world (fireflies, rotten, etc.). Artificial light sources, depending on what process underlies the production of radiation, are divided intothermal andluminescent. - Give examples of natural and artificial light sources.Since light is electromagnetic radiation and all the properties of electromagnetic waves are inherent in it, all problems of optics can be solved on the basis of wave representations. However, this requires the use of a very cumbersome mathematical apparatus. However, when solving problems of constructing images in mirrors and lenses and when calculating optical devices, scientists use geometric methods. These methods make up the contentgeometric optics, otherwise calledradial optics. The basic concepts of geometric optics arebeam and beam. Moreover, these concepts cannot be identified. A beam of light can be observed, and a beam can only be drawn on paper: -cylindrical or conical channels through which light propagates are calledlight beams ; - beam called a geometric line indicating the direction of the transfer of light energy. Now the differences between these physical concepts and their figurative and literary “analogues” such as “rays of the Sun”, “a ray of light fell on the table”, “Katerina is a ray of light in a dark kingdom” and so on are obvious. There are no infinitely narrow beams of light; a beam of light always has a finite width. The beam is, as it were, the axis of the beam, and not the beam itself.Geometric optics is based on three laws: a) the law of rectilinear propagation of light; b) the law of reflection of light; c) the law of refraction of light.Light in a homogeneous medium propagates in a straight line - this is how the law of rectilinear propagation of light is formulated. What examples can you give to confirm the rectilinear propagation of light?Optically homogeneous A medium is considered to be one in which light travels at a constant speed. If there are two media in which light travels at different speeds, then the medium where light travels at a slower speed is calledoptically denser, and a medium where light travels at a faster speed -optically less dense. Shade and penumbra. The straightness of light propagation is confirmed by the formationshadows. If we take a small source of light, a screen, and place an opaque object between them, then a dark image of its outline will appear on the screen - a shadow.A shadow is an area of ​​space that does not receive light energy from a light source. - Why does the formation of a shadow serve as proof of the rectilinear propagation of light? In the experiment, we did not take into account the dimensions of the light source. A light source whose dimensions are small compared to the distance from the screen is calledpoint source of light. If we take a larger light source, then penumbra is also formed around the shadow on the screen.Penumbra - a region of space into which light energy from a light source partially enters. The formation of shadow and penumbra explains solar and lunar eclipses.During a solar eclipse the full shadow of the moon falls on the earth. From this place on Earth, the Sun is not visible. When the Moon, revolving around the Earth, falls into its shadow, then there ismoon eclipse. At the end of the lesson, you can talk about the practical use of the law of rectilinear propagation of light (construction, laying roads, determining the height of objects, and so on).

student responses,

group work,

result

1 min

Fizminutka

Basics

part (15min)

View PPT presentation.Video viewing

We pose the problem: Group work: Strategy "Snowball" - the teacher invites students to prepare speeches on:

1 group "Sun": What is light? What bodies are the sources of light? How does the radiation of an iron or boiler differ from the radiation of an electric incandescent lamp?The star is the sun. The law of rectilinear propagation of light.

2.group "Moon": What is meant in physics by the terms ray, beam of light, point source of light?Shade and penumbra. Solar and Lunar eclipses.Give examples.

Individual work: Knowledge self-test

Test:

1. Light radiation....?

A. ... makes various bodies visible;

B. Perceived by the eye; C. Radiates a heated body.

2 . Light sources are

A. ...only natural.B. ... only artificial ones.

B. ... natural and artificial

3 . What is a point light source?

A. Luminous body of small size.

B. a source whose dimensions are much smaller than the distance to it.

B. A very weakly luminous body.

4 . How does light propagate in a homogeneous medium?

A. straight. B. curvilinear.

B. Along any line connecting the source and the subject.

5 . How are light sources classified?

A. natural and artificial

B. mechanical. thermal

6. What is the source of visible light?

A) a heated electric kettle

B) Television antenna. C) Arc during welding

7 . Among the listed sources does not emit light?

A) Bonfire; B) Radiator; C) Sun.

8. What is the shadow?

A) A region of space where, due to rectilinear propagation, light does not fall.

B). Dark place behind the subject

B) dark place

9. What is penumbra? What should be the source.

A) A place where half of the world falls. Extended.

B) A place where there is light, but it is not enough.

C) A region of space where there is both shadow and light. Dotted.

10. Which line is called a light beam?

A) a line emanating from a light source

B Line, the will of which is distributed by energy from a light source.

C) The line along which light from a source enters the eye.

Examination right answers appear on click

2. In

3. B

4. In

5.A

6.B

7. A

8. B

9B

Students watch the presentation

presentation discussion,

work with the textbook.

Group work: Snowball strategy:

Students individually write down their thoughts and opinions.

(discuss their positions and reach a compromise on this issue and write down the result).

Create a poster by entering concepts in accordance with the topic.

At the end of the discussions, students defend the work of the group, where they state their understanding of the topic, summarize, justify their point of view, demonstrate the ability to argue their opinion; appraisal skills.

Poster protection.

Group work, self-regulation.

Students take tests.

self-assessment

0 errors - 5

1-2 mistakes - 4

3-4 mistakes - 3

5-6 mistakes - 2

Conclusion

reader

part (8min)

We solve quality problems.

1. How can light sources be positioned so that during the operation the shadow from the surgeon's hands does not cover the operation site?

Answer : Arrange several lamps overhead

2. Why don't objects cast shadows on a cloudy day?

Answer : Objects are illuminated by diffused light, the illumination from all sides is the same.

3. Is it possible to observe solar and lunar eclipses from any point on the Earth's surface?

Answer : Lunar yes. Solar no.

4. Can a cyclist overtake his own shadow?

Answer : Yes, if a shadow is formed on a wall parallel to which the cyclist is moving, and the light source is moving faster than the cyclist in the same direction.

5. How does the size of the penumbra depend on the size of the light source?

Answer : The larger the source, the greater the penumbra.

6. Under what condition should the body give a sharp shadow on the screen without penumbra?

Answer : When the size of the light source is much smaller than the size of the body.

Guys! In conclusion, I want to say. The physicist sees what everyone sees: objects and phenomena. He, like everyone else, admires the beauty and grandeur of the world, but behind this beauty accessible to everyone, he discovers another beauty of patterns in an endless variety of things and events.

Love, children, physics!
She is always, everywhere.
Helps you to be able
Both in life and in work!

Lesson summary (3min)

Summing up the lesson

assessment,

mutual evaluation

Strategy "Two stars and a desire" - students give 2 stars and write down for what, express one desire, which, in their opinion, will improve this work.

A word to the expert council

Reflection "Starry sky"

Home.zad.

(2 minutes)

§61,62,63

Grateful High School

Open lesson in physics in 8 "B" class on the topic

Prepared by physics teacher Kuspakova R.T.

Aktobe

2015-2016 academic year

Sources of light. Spread of light

1. Light is radiation that ...

a) ...makes different bodies visible.

b) ...perceived by the human eye.

c) ... heats illuminated objects.

d) ... emits a heated body.

2. Light sources are...

a) ... only natural ones.

b) ... only artificial ones.

c) ... mixed.

d) ... natural or artificial.

3. How are light sources divided depending on the phenomenon that causes the body to glow?

a) Thermal and luminescent.

b) Thermal and electrical.

c) Thermal and mechanical.

d) Luminescent and magnetic.

4. What light source is called a point?

a) The luminous body is very small.

b) A source located at a very large distance from the observer.

c) A source whose dimensions are much smaller than the distance to it.

d) A very weakly luminous body.

5. What line is called a light beam?

a) A line that comes from a light source.

b) The line along which the energy from the light source propagates.

c) The line along which light from a source enters the human eye.

d) None of the answers are correct.

6. How does light propagate in a homogeneous medium?

a) Straight line.

b) Curvilinear.

c) Along the arc of a circle passing through the light source and the human eye.

d) Along any line connecting the light source and the illuminated object.

Light must enter our eyes in order for us to see something. If we close our eyes or enter a dark room, we will not see anything. The visual world can only be perceived through our vision.

Light sources are bodies that emit light - the sun, a lamp, a candle, etc.

Our eye also perceives light from those bodies that are illuminated by some source of light. All bodies are capable of reflecting light to a greater or lesser extent.

Shadow

Light propagates in a straight line. A beam of light is seen especially well if there are dust particles or water droplets in the air that reflect light.

If a ray of light falls on an opaque object, then an unlit spot appears behind it, called a shadow. Depending on how far the object is from the light source, the size of the shadow may vary.

If we illuminate an object with two lamps that stand side by side, then two shadows appear, partially overlapping one another.

Places that are not illuminated by any source are called direct shadows. Unlike a direct shadow, a penumbra is formed by the superimposition of shadow and light.

The sun constantly illuminates the moon. Since the Moon makes a complete revolution around the Earth in 28 days, we can observe the degree of illumination of the Moon's surface over time.

At the new moon, the Moon is between the Sun and the Earth in such a way that its illuminated part is not visible to us.

The moon is growing, and we see more and more illuminated part of the surface. On a full moon, we observe the fully illuminated surface of the moon.

As the Moon wanes, the illuminated part visible from the Earth also slowly disappears, until the Moon turns into a thin crescent.

Once every 1.5 years, the trajectory of the Moon crosses the trajectory of the Earth, so the Moon falls into the shadow cast by the Earth.

It is then that the Moon is not illuminated by the Sun, and we do not see it. This is called a lunar eclipse.

Approximately once every 2.5 years, the Moon is located between the Sun and the Earth. At this point, a partial solar eclipse can be observed. If you are on Earth in the place where the Moon casts a shadow, the diameter of which is about 260 km, then you can see a total eclipse of the Sun. But this phenomenon is very rare and is repeated no more than once every 200 years.

When illuminated by a light source, the dimensions of which are comparable both with the dimensions of the body and with the distance between the source and the body. Penumbra is the periphery (outer part) of the darkened area. In the penumbra, only part of the light source is visible. In this it differs both from a full shadow, in which the source is not visible at all, and from full light: in the light it is completely visible.

The penumbra (outer part of the shadow) from a celestial body can be observed, for example, during a partial eclipse of the Sun, when the observation point falls into the penumbra formed by the Moon in a stream of sunlight.

In the fine arts, in particular in photography, penumbra is understood not so much as space as an area of ​​the body surface as an element of chiaroscuro - a weak shadow, a gradation of chiaroscuro on the surface of an object, occupying an intermediate position between light and deep shadow. Penumbra occurs when an object is illuminated by several light sources, on a surface facing the light source at a slight angle.

In everyday speech, penumbra can be called any thin (weak, transparent, pale shadow) that occurs in low light.

Literature

• Yashtold-Govorko V. A. Penumbra // Yashtold-Govorko V. A. Photography and processing. Shooting, formulas, terms, recipes. Ed. 4th, abbr. M., Art, 1977.

Wikimedia Foundation. 2010 .

Synonyms:

See what "Penumula" is in other dictionaries:

Penumbra … Spelling Dictionary

The space between the regions of full shadow and full light, formed behind an opaque body when it is illuminated by a light source with large angular dimensions (Fig.). In the P. region, only part of the source is visible (in the shadow, the source is not visible at all). ... ... Physical Encyclopedia

Penumbra, penumbra, about penumbra, in penumbra, wives. Sparse shade, very dimly lit place. “Slightly noticeable in the penumbra is a distant threshing floor.” A.K. Tolstoy. Explanatory Dictionary of Ushakov. D.N. Ushakov. 1935 1940 ... Explanatory Dictionary of Ushakov

PUMMON, and, about penumbra, in partial shade and in partial shade, pl. and, her and her, wives. Weak transparent shadow. In the shade of the leaves. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

Exist., number of synonyms: 2 shade (34) chiaroscuro (3) ASIS synonym dictionary. V.N. Trishin. 2013 ... Synonym dictionary

penumbra- penumbra, kind. penumbra, preposition about the penumbra, in the penumbra and in the penumbra; pl. penumbra, kind. penumbra and obsolete penumbra ... Dictionary of pronunciation and stress difficulties in modern Russian

The space between areas of full shadow and full light. It is formed behind an opaque body when it is illuminated by a light source, the dimensions of which are comparable both with the dimensions of the body and with the distance between the source and the body (Fig.). In area… … Great Soviet Encyclopedia

penumbra- pusšešėlis statusas T sritis fizika atitikmenys: angl. half shade; partial shadow; penumbra vok. Halbschatten, m; Penumbra, f rus. penumbra, f pranc. pénombre, f … Fizikos terminų žodynas

G. 1. Sparse, pale shadow. 2. A dimly lit space between full shadow and full light. Explanatory Dictionary of Ephraim. T. F. Efremova. 2000... Modern explanatory dictionary of the Russian language Efremova

1. penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra 2. penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, penumbra, ... … word forms