Agreeing Disagreeing

-Absoluteli! - I don’t agree.

- You are right. – I don’t think so.

- That’s true. – I’m not sure …

- I quite agree. – I wouldn’t say that.

1. The distance along the bottom of the wing is greater than the distance over the top of it.

2. The air flowing over the top travels faster than the air flowing along the bottom of the wing.

3. The faster a gas flows, the more pressure it creates.

4. The pressure of the faster-flowing air on the bottom of the wing is less than that of the slower-moving air on the top.

5. The increased pressure differential results in greater lift and thrust.

6. The thrust and drag depend on the angle of attack.

7. When thrust becomes more than drag, the airspeed decreases rapidly.

8. The thrust pushes the plane forward overcoming the resistance of the air against the plane.

9. The lift of an airplane acts vertically upwards and its weight – vertically downwards.

10. The lift being equal to the weight, the airplane climbs; if the two forces are unequal the plane descends.

6. Answer the questions.

1. Why is the plane able to fly in the air?

2. What are the forces acting on it?

3. What happens in the air when an airfoil moves through it?

4. How does the air flow over and under the wing?

5. What does the air stream create on the top and bottom of the wing?

6. What does the pressure differential results in?

7. What condition is necessary for producing lift?

8. How may thrust be created?

9. What is the drag?

10. How do the four forces act? What is their nature?

11. What are the means of producing lift and thrust?

12. What does the straight-and-level flight mean?

13. What do the lift and drag depend on?

Vocabulary Focus

1. Match the word in column A with the word in column B having a similar meaning. Be careful, there are some extra words in column B.

A B

stream decrease

travel rear

airfoil support

join not curved

produce move

straight flow

maintain operate

act create

reduce connect

artificial aerodynamic surface

trailing man-made

leading

increase

Match the antonyms.

A B

lift weight

thrust slow

climb backward

bottom rear

flat natural

upper drag

fast upward

artificial descent

forward lower

front curved

downward top

<== попередня сторінка	\|	наступна сторінка ==>
In the text find the definition of lifting force and air resistance.	\|	Choose the best alternative to fill the gaps in these sentences.

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