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In pairs, discuss what is meant by “complex machines”. Give examples of such machines.
Содержание книги
- Write questions in the Present Perfect Tense.
- Match the first part of the sentence (1-7) with the second one (A-G).
- Listen again and answer the questions.
- These tasks can help you to practise The Past Simple Tense (See Appendix 1 p. 214 – 218) and do the following exercises.
- Write these sentences into the Present Simple negative form.
- Fill in the words from the list below. Use each word only once.
- Pre-listening. Match the English words on the left to their Ukrainian equivalents on the right.
- Some of the following sentences contain mistakes. Find the mistakes and correct them.
- Look at the pictures which show the problems of the environment and match the suggestions with their problems.
- Pre-listening: match the words on the left to the words on the right.
- Listen to three people taking part in a survey about recycling. Mark statements as Yes (Ö) or No (c).
- Put the verbs in brackets into the correct tense.
- What is force? Give examples of forces acting on people and objects around us.
- Match the first part of the sentence (1-7) with the second one (A-G).
- Think of examples of natural materials that can change shape or colour, or repair themselves. Discuss with your partner what forces are used in these processes.
- Put the verbs in brackets into the Future Simple Tense, the Present Simple Tense, the Present Continuous Tense or the correct form of be going to.
- What do you know about the forces of gravity, friction and magnetism? How do they influence our lives?
- Fill in the words from the list below. Use each word only once.
- Pre-listening: match the English words and phrases in the left column with their Ukrainian equivalents in the right column.
- force of gravity - magnetism - north/south pole
- In pairs, discuss what is meant by “simple machines”. Are they still in use today? If yes, give some examples.
- Match the first part of the sentence (1-7) with the second one (A-G).
- Pre-listening: match the English words and phrases in the left column with their Ukrainian equivalents in the right column.
- to improve production processes - equipment
- Fill in the gaps with the proper item.
- In pairs, discuss what is meant by “complex machines”. Give examples of such machines.
- Match the first part of the sentence (1-7) with the second one (A-G).
- These tasks can help you to practise grammar topic “The Modals: Permission - Obligation” (See Appendix 1 p. 230 – 234) and do the following exercises.
- Complete the sentences with should or shouldn't and the words in brackets.
- Name as many metals as you can? Where are they used?
- Fill in the words from the list below. Use each word only once.
- Do you agree with the following proverbs? Discuss them with your classmates.
- Put the verbs in brackets into the Present Simple Passive.
- Look at the objects in the pictures. What materials do you think they are made of and why?
- Match each word from the text with its synonym.
- Listen to the text and complete the sentences.
- design and construction - dimensions of the object
- Put the questions into the Passive Voice.
- Listen to the conversations. Write the numbers.
- Work in pairs. What numbers do people usually consider lucky and unlucky and why?
- Translate the following sentences into English.
- Pre-listening match the words from the left column with their Ukrainian equivalents in the right column.
- Listen to the text and complete the sentences.
- Match the items in two columns in order to make correct Type 0 conditional sentences, as in the example.
- What other geometric figures do you know? Name the objects in the classroom that have the shape of a circle, triangle, square, rectangle, oval, arc, cube, cylinder, hexagon, etc.
- Fill in the words from the list below. Use each word only once.
- Listen to the text and answer the following questions.
- Use the information from the table to complete the sentences below.
- Match the measuring instruments to their names.
- Pre-listening: match the words in the left column with their Ukrainian equivalents in the right column.
2. In pairs, discuss what is meant by “complex machines”. Give examples of such machines.
READING
3. Read the text and match the questions (a-g) to the paragraphs (1-7):
a. What is a complex machine?
b. What kind of machines are inclined plane, wedge, screw, lever, wheel and axle, and pulley?
c. What makes an automobile a complicated complex machine?
d. Which simple machines are used in doorknobs and scissors?
e. What simple machines are used in a computer?
f. Which modern machines use gears?
g. What simple machines does a bicycle combine?
Complex Machines
You have already known about the six simple machines: inclined plane, wedge, screw, lever, wheel and axle, and pulley. You've probably figured out that these six machines were invented ages and ages ago. So what has been happening since then? Did someone invent simple machine number 7, 8, 9, 10, and so on?
Let’s look at a bicycle for an example. A bicycle is a much newer machine than the simple lever that a cave man used to move a big old rock, but it’s not as new as, say, a laptop computer. A bicycle is not number 7, or 100, or even 1000. A bicycle is actually a combination of several of those six basic simple machines. A bicycle gear is actually a combination of simple machines all by itself. A gear is a wheel, but the teeth on the gear are little wedges. What other simple machines can you find on a bicycle?
Gears, along with other simple machines, make up many of the machines you use every day. Some examples are the lawn sprinkler, a watch, and the gearbox in a car. Escalators and elevators use combinations of simple machines. So does a hand drill. So do sewing machines, parking meters, and windmills.
The doorknob is a wheel and axle system that transfers the force applied by a person to a system of levers. The levers move the bolt and unlatch the door. A pair of pliers is really two Class 1 levers with the same fulcrum (the pivot pin). A pair of scissors is a pair of pliers with wedges as the cutting edge.
Machines that use a combination of two or more simple machines are called complex machines. Machines can do all kinds of jobs today and make our lives easier in many ways.
Some complex machines are very complicated. An automobile is one such machine. The engine contains many levers, wheels and axles, and pulleys. The whole engine is held together by threaded bolts, which are a form of inclined plane. The transmission uses gears, which are a form of wheel and axle with specially shaped teeth on the outside of the wheels. Two gears fit together and transfer force and power from one gear shaft to another. By choosing the size of the gears, the speed and direction of the rotation of the axles can be controlled.
Even devices that do not seem to be mechanical use simple machines. A computer, which is thought of as an electronic device, has a cooling fan. This fan is a complex machine in which the motor shaft turns the fan, which is a form of wheel. The disk drive uses a wheel and axle to turn the disk and a system of levers to position the heads that read and write the data on the disk.
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