In the text find the definition of lifting force and air resistance.
3. Complete the following sentences with suitable words from the text:
1. The aircraft is able to keep in the air because of …….
2. It produces an upward force which ……
3. Part of the air flows over the wing and …
4. The air flowing under the bottom of the wing travels …..
5. The air moving across the top of the wing creates …
6. The difference in pressure between ….
7. To produce lift the wing must ….
8. A force of thrust acts ……
9. The resistance the aeroplane meets …
10. The aeroplane is acted upon by …
11. Drag and weight are forces ….
12. Thrust and lift are …..
13. Thrust is produced by ….
14. Inequality between lift and weight results in ….
15. Inequality between thrust and drag results in …..
These are the definitions. Guess the terms.
1. The force that acts on the airplane wing in a direction perpendicular to the air stream.
2. The resistance the airplane meets in moving through the air.
3. A force producing a high speed of the airplane.
4. A force with which a body tends toward the centre of the Earth.
5. Blades fixed to a revolving shaft for driving an aircraft.
6. A device which is capable of producing lift when it is moved through the air.
Agree or disagree with the statements. Use conventional formulae of agreement and disagreement.
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