Grammar. Participle as Adjectives (Participle I and Participle II).

Exercise 25. Circle the correct form of the participles used as adjectives in the following sentences.

1. The (breaking/ broken) dishes lay on the floor.

2. The (trembling/ trembled) children were given a blanket for warmth.

3. Compassionate friends tried to console the (crying/ cried) victims of the accident.

4. The (interesting/ interested) tennis match caused a great deal of excitement.

5. When James noticed the (burning/ burnt) building, he notified the fire department immediately.

6. The (exciting/ excited) passengers jumped into the lifeboats when notified that the ship was sinking.

7. The (smiling/ smiled) ‘Mona Lisa’ is on display in the Louver in Paris.

8. The wind made such (frightening/ frightened) noises that the children ran to their parents’ room.

9. The (frightening/ frightened) hostages only wanted to be left alone.

10. We saw the (advancing/ advanced) army from across town.

11. Mrs. Harris’s (approving/approved) smile let us know that our speeches were well done.

12. Our representative presented the (approving/ approved) plan to the public.

13. The food of that new restaurant was (disgusted/ disgusting).

Exercise 26. Rewrite the sentences using a participle clause.

Look at the woman who is dressed in blue. = Look at the woman dressed in blue.

The boy who is sitting next to the lady is my cousin. = The boy sitting next to the lady is my cousin.

1. The boy who was injured in the accident is still in hospital.

2. Cars which are made in Germany are usually expensive.

3. I gave some sweets for the small girl who was crying in the park.

4. I know an Italian restaurant which serves excellent spaghetti.

5. The boy who is making so much noise is my son.

6. The grammar books which were printed last week will be sent to all school.

7. I’d like to stay in a room that overlooks the sea.

8. The purse which was stolen from the room was found by police.

9. Many people who live in large cities hate crowds.

10. The snow which is falling on highway will make traveling dangerous.

Exercise 27. Join these sentences using present participle or perfect participle form.

Examples:

· I looked out of window. I saw my friend. = Looking out of window, I saw my friend.

· I took a shower, and then I went to work. = Having taken a shower, I went to work.

· As the children had been warned not to stay out too long, they came home early. =Having been warned not to stay out too long, they came home early.

1. The man didn’t want to see this girl, so he quickly went in the small room. 2. Suzy tried to phone her boyfriend but she didn’t realize that the telephone was out of order. 3. He had worked all his life, so he decided to take a long holiday.4. She had finished all the house work, and then she sat on the sofa to watch TV. 5. He failed the exam because he hadn’t studied.6. Jane is busy in the kitchen. She is cooking some fish for visitors. 7. As she had been advised by her doctor to lose weight, she started to go on diet.8. As I have never met your secretary before, I’m surprised to see how beautiful she is.9. The lady opened the door quietly and she saw her maid stealing the jewellery in drawer. 10. He had driven all day, so he was glad to get home and rest.

Writing

Exercise 28. Translate the sentences into English using active vocabulary and paying attention to translation of Participle (words in italics).

1. На межі поділу двох середовищ частина світла відбивається, а частина – заломлюється. 2. Кутом падіння називається кут між падаючим променем та перпендикуляром до межі поділу, проведеним у точці падіння. 3. Кут відбивання – це кут між відбитим променем і тим самим перпендикуляром. 4. Закони відбивання світла можна сформулювати наступним чином: a) Падаючий промінь, відбитий промінь і перпендикуляр до межі поділу двох середовищ, проведений у точці падіння променя, лежать в одній площині. б) Кут відбитого променя дорівнює куту падаючого променя. 5. Знаючи закони відбивання світла, легко пояснити, як відбуваються дзеркальне і розсіяне відбивання світла. 6. Якщо паралельні промені, які падають на поверхню, залишаються паралельними і після відбивання, то таке відбивання називається дзеркальним, а сама поверхня – плоским дзеркалом. 7. Дзеркальну, тобто гладеньку, поверхню використовують тоді, коли світловий пучок потрібно повернути в певному напрямку. 8. Якщо паралельний пучок світла падає на шорстку поверхню, перпендикуляри в точки падіння не є паралельними, тому відбиті промені також не є паралельними; і світло поширюється в різні сторони. 9. Розсіяним є відбивання світла, що падає на сторінки книг, зошитів, від поверхні Землі, Місяця. 10. Тому текст ми можемо читати при будь-якому положенні очей відносно книги, а Місяць бачимо, пересуваючись по Землі.

Exercise 29. Summarize all the information given in unit 2 and write the summary under the title ‘Reflection. Specular and Diffuse reflection’.

Unit 3. Refraction.

Active vocabulary

1. Alter ['ɔːltə] змінювати(ся)

2. Angle of refractio ['æŋgl] [rɪ'frækʃən]кут заломлення

3. (To) bend [bend] згинати(ся)

4. Dispersion [dɪs'pɜːʃ(ə)n] дисперсія

5. (To) distort [dɪs'tɔːt] викривляти

6. Distorted image [dɪ'stɔːtɪd'ɪmɪʤ] викривлене зображення

7. Fata Morgana [ˌfɑːtəmɔː'gɑːnə] фата-моргана, марево

8. (To) i nteract [ˌɪntər'ækt] взаємодіяти

9. Line of sight [laɪn] [saɪt] лінія прямої видимості

10. (To) magnify ['mægnɪfaɪ] збільшувати

11. Medium (pl. media) ['miːdɪəm] ['miːdɪə] середовище (cередовища)

12. Mirage ['mɪrɑːʒ] міраж

13. Optical phenomenon (pl. phenomena) оптичне явище (явища)

['ɔptɪk(ə)l fɪ'nɔmɪnən], [fɪ'nɔmɪnə]

14. Prism [prɪz(ə)m] призма

15. Rainbow ['reɪnbəu] веселка, райдуга

16. (To) refract [rɪ'frækt] заломлювати

17. Refraction [rɪ'frækʃ(ə)n] заломлення, рефракція

18. Refractive index (indices) [ri'fræktɪvˌindeks] показник заломлення

19. Sound wave ['saundweɪv] звукова хвиля

20. (To) split ['splɪt] розщеплювати

Pre-reading task

Exercise 30. In pairs, discuss the following questions.

1. Where can you see a rainbow? Why are rainbows called rainbows?

What colours does a rainbow spectrum include?

2. What is a mirage? Have you ever heard about Fata Morgana? What is it?

Reading

Exercise 31. Read, translate the text and find the words which correspond with these descriptions.

1. an optical illusion in which atmospheric refraction by a layer of hot air distorts or inverts reflections of distant objects. _____________

2. The bending of any wave, such as a light or sound wave, when it passes from one medium into another of different density. ____________

3. An arc of spectral colors, usually identified as red, orange, yellow, green, blue, etc, that appears in the sky opposite the sun as a result of the refractive dispersion of sunlight in drops of rain or mist. ____________

4. A surface forming a common boundary between two media. ________

5. A mirage consisting of multiple images, as of cliffs and buildings, that are distorted and magnified to resemble elaborate castles, often seen near the Straits of Messina. _____________

6. The ratio of the velocity of light in a vacuum to its velocity in a specified medium. _______________

REFRACTION

When electromagnetic radiation, in the form of visible light, travels from one substance or medium into another, the light waves may undergo a phenomenon known as refraction, which is manifested by a bending or change in direction of the light. Refraction occurs as light passes from one medium to another only when there is a difference in the index of refraction between the two materials. The effects of refraction are responsible for a variety of familiar phenomena, such as the apparent bending of an object that is partially submerged in water and the mirages observed on a hot, sandy desert. The refraction of visible light is also an important characteristic of lenses that enables them to focus a beam of light onto a single point.

Refraction is the bending of a wave as it crosses the boundary between two media at an angle. Refraction of light occurs at the interface between two media of different refractive indices, with n₂ > n₁. Since the phase velocity is lower in the second medium (v₂ < v₁), the angle of refraction θ₂ is less than the angle of incidence θ₁; that is, the ray in the higher-index medium is closer to the normal.

Refraction is the change in direction of a wave due to a change in its speed. Sound waves are refracted when parts of a wave front travel at different speeds. Sound wave refraction occurs in uneven winds or when sound is travelling through air of uneven temperature. On a cold day or night, when the layer of air near the ground is colder than the air above it, the speed of sound near the ground is reduced. The higher speeds of the wave fronts above cause a bending of the sound toward Earth. When it happens, sound can be heard over considerably longer distances.

Changes in the speed of light as it passes from one medium to another, or variations in the temperatures and densities of the same medium, cause refraction. When light rays enter a medium in which their speed decreases, as when passing from air into water, the rays bend toward the normal. When light rays enter a medium in which their speed increases, as when passing from water into air, the rays bend away from the normal.

Fig. 6.8.

Refraction occurs when light waves travel from a medium with a given refractive index to a medium with another. At the boundary between the media, the wave's phase velocity is altered, it changes direction, and its wavelength increases or decreases but its frequency remains constant. Refraction can be seen when looking into a bowl of water. Air has a refractive index of about 1.0003, and water has a refractive index of about 1.33. If a person looks at a straight object, such as a pencil or straw, which is placed at a slant, partially in the water, the object appears to bend at the water's surface (Fig. 6.8). This is due to the bending of light rays as they move from the water to the air. Once the rays reach the eye, the eye traces them back as straight lines (lines of sight). The lines of sight intersect at a higher position than where the actual rays originated. This causes the pencil to appear higher and the water to appear shallower than it really is. The depth that the water appears to be when viewed from above is known as the apparent depth.

Fig. 6.9. A rainbow.

Refraction is also responsible for rainbows (Fig. 6.9) and for the splitting of white light into a rainbow-spectrum as it passes through a glass prism. Glass has a higher refractive index than air and the different frequencies of light travel at different speeds (dispersion), causing them to be refracted at different angles, so that you can see them. The different frequencies correspond to different colors observed. While refraction allows for beautiful phenomena such as rainbows it may also produce peculiar optical phenomena, such as mirages and Fata Morgana.

Fig. 6.10. Fata Morgana

The appearance of distorted image that forms as the result of atmospheric refraction is called a mirage. A mirage and Fata Morgana (Fig. 6.10) are caused by the refraction of light in Earth’s atmosphere (from ‘Conceptual Physics’).

Exercise 32. Answer the questions to the text.

1. What is refraction? When does it occur?

2. What phenomena is refraction responsible for?

3. Why is the speed of sound reduced near the ground on a cold day?

4. What happens when you look at a pencil placed at slant in a glass of water?

5. What is the apparent depth?

6. What is a rainbow? How can this phenomenon be explained?

7. What is a mirage?

8. What are a mirage and Fata Morgana caused by?

Exercise 33. Match the words in columns A and B to make word combinations. Translate them into Ukrainian.

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