Ex.8. Translate into English.

1. While we were crossing the bridge, we saw a man, who was talking with our father.2. As we were very tired, we refused to go for a wolk.3. As the boys had climbed the mountains the summer before, they understood the difficulties.4. A large branch, which had been broken by the wind, lay across the road.5. At a conference, a number of important scientific problems are being discussed.6. A person bringing good news is always welcome.7. While skating yesterday, he fell and hurt himself.8. When writing a telegram we must use as few as possible.9. The leaves lying on the ground reminded us of autumn.10. Arranging everything, he could come home very late.

Unit 6

Theme:MACHINES AND WORK

Grammar: Participle II

Objectives: By the end of this unit, students should be able to use active vocabulary of this theme in different forms of speech exercises.

Students should be better at discussing human rights.

Students should know the rule of Infinitive Constructions and fulfill grammar exercises.

 

Methodical instructions: This theme must be worked out during two lessons a week according to timetable.

Lexical material: Introduce and fix new vocabulary on theme “Rocket engines engineering”.

Lexical material: Introduce and fix new vocabulary on theme “Rocket engines engineering”.

Define the basic styles in rocket engineering and its role in our country. Discuss in groups “High energy automatic systems engineering”.

Grammar: Introduce and practice The Complex Subject. Revise the use of Continuous and Perfect Tenses.

MACHINES AND WORK

Defined in the simplest terms a machine is a device that uses force to accomplish something. More technically, it is a device that transmits and changes force or motion into work. This definition implies that a machine must have moving parts. A machine can be very simple, like a block and tackle to raise a heavy weight, or very complex, like a railroad locomotive or the mechanical systems used for industrial processes.

A machine receives input from an energy source and transforms it into output in the form of mechanical or electrical energy. Machines whose input is a natural source of energy are called prime movers. Natural sources of energy include wind, water, steam, and petroleum. Windmills and waterwheels are prime movers; so are the great turbines driven by water or steam that turn the generators that produce electricity; and so are internal combustion engines that use petroleum products as fuel. Electric motors are not prime movers, since an alternating current of electricity which supplies most electrical energy does not exist in nature.

The terms like work, force, and power are frequently used in mechanical engineering, so it is necessary to define them precisely. Force is an effort that results in motion or physical change. If you use your muscles to lift a box you are exerting force on that box. The water which strikes the blades of a turbine is an exerting force on those blades, thereby setting them in motion.

In a technical sense work is the combination of the force and the distance through which it is exerted.

To produce work, a force must act through a distance. If you stand and hold a twenty-pound weight for any length of time, you may get very tired, but you are not doing work in an engineering sense because the force you exerted to hold up the weight was not acting through a distance. However, if you raised the weight, you would be doing work.

Power is another term used in a special technical sense when speaking of machines. It is the rate at which work is performed.

In the English-speaking countries, the rate of doing work is usually given in terms of horsepower, often abbreviated hp. You will remember that this expression resulted from the desire of the inventor James Watt to describe the work his steam engines performed in terms that his customers could easily understand. After much experimentation, he settled on a rate of 33,000 footpounds per minute as one horsepower.

In the metric system power is measured in terms of watts and kilowatts. The kilowatt, a more widely used term, equals a thousand watts or approximately 1/3 horsepower in the English system.

 

Упражнение 3. Соедините термин с соответствующим ему определением, данным в правой колонке.

Machine   Prime mover	is	the rate at which work is performed   a device that uses force to accomplish something
Force   Work   Power	is	an effort that results in motion or physical change   a machine whose input is a natural source of energy   a combination of the force and the distance through which it is exerted

Упражнение 4. Прочитайте внимательно два последних абзаца и заполните сле-дующую таблицу, в которой должно быть показано соотношение между единицами мощности в разных системах.

 

Единицы мощности	Эквивалент
Обозначение	Полное название	Перевод
hp	horse power	лошадиная сила	33,000 foot-pounds per minute
w kw	… …	… …	… …

Упражнение 5. Распределите следующие слова в три группы: а) обозначающие основные понятия физики и механики; б) обозначающие источники энергии; в) меха-низмы, машины:

wind, power, water, force, work, steam, wind mill, petroleum, turbine, motion, weight, block, device, locomotive, input, output, steam engine, rate, effort, distance, generator, part, weight.

Упражнение 6. Следующие глаголы часто сочетаются с понятиями физики и механики. Составьте с ними глагольные сочетания, используя материал текста.

Model: to transmit − to transmit motion / force

to produce, to transform, to supply, to result in, to exert, to set, to perform, to result from, to measure... in.

Упражнение 7. Изучите внимательно второй абзац текста еще раз и сгруппируйте следующие существительные в таблицу:

wind mill, wind wheel, steam engine, electric motor, internal combustion engine, turbine.

Вид двигателя	Энергия на входе
Prime-mover Non-prime-mover	The input is a natural source of energy. The input is a source of energy that does not exist in nature

 

Упражнение 8. Подготовьте развернутые ответы на следующие вопросы:

1. What is a simple definition of a machine? What is a more technical definition? What does this definition imply? 2. Describe some very simple machines. What are some complex ones?
3. What are the machines called whose input is a natural source of energy? What are some natural sources of energy and the machines that use them? 4. Why aren't electric motors prime-movers? 5. What is force? Give some examples. 6. What is work? How can work be expressed mathematically? Give an example. 7. What is power? 8. How is the rate of doing work usually given in the English-speaking countries? Why was the term invented? 9. In what terms is power measured in the metric system?

 

Grammar: Non-finite form of the verb: Participle II.

The form of Participle II is regular verbs by adding –ed or –d to the Infinitive and the past participle of irregular verbs

It uses:

· As an adjective; stolen money

· To form the perfect tenses/infinitives and participles and the passive voice: he has seen, it was broken, to have loved.

· The participle II can replace a subject + passive verb as the participle I can replace subject + active form: She enters. She is accompanied by her mother./ She enters, accompanied by her mother.

 

Ex.5. Translate the sentences into English. Use the present participle instead of the italicized verbs.

1. Мы оставили ему записку и отправились на прогулку в парк.2. Он открыл книгу и показал мне подчеркнутое место.3. Она улыбнулась и вышла из комнаты.4. Она тяжело вздохнула и налила себе вторую чашку кофе.5. Мы оставили чемоданы в камере хранения и отправились на поиски комнаты.6. Она медленно печатала что-то на машинке и иногда спрашивала меня, как пишется то или другое слово.

 

Ex.6. Translate the sentences from English into Russian.

1. Informed of the arrival of the ship, they sent a car to the port.2. She showed the travelers the room reserved for them3. Books read in childhood seem like old friends.4. The answer received from her greatly surprised us.5. The figures mentioned in his article were published in “Izvestia”.6. Having left in that town all his life, he knew it very well.