Question

7.To sharpen the blade of a knife by rubbing it against a surface, which of the following will

be most suitable?

(a) Stone

(b) Plastic block

(c) Wooden block

(d) Glass block

8.The shape of an aeroplane is like a

(a) dog

(b) bird

(c) car

(d) all of these

9.Friction is

(a) foe

(b) friend

(c) both (a) and (b)

(d) none of these

10.Friction due to fluids is called

(a) force

(b) pressure

(c) friction

(d) drag

11.Which of the following is not a smooth surface?

(a) Surface of wet soap

(b) Surface of tyres

(c) Glazed tiles

(d) Surface of mirror

12.A toy car released with the same initial speed will travel farthest on

(a) muddy surface

(b) polished marble surface

(c) cemented surface

(d) brick surface

13.If we apply oil on door hinges, the friction will

(a) increase

(b) decrease

(c) disappear altogether

(d) will remain unchanged

14.Lubricant

(a) reduce friction

(b) increase friction
(c) both (a) and (b)

(d) none of these​

Answer 1

Answer:

1. Stone

2. Bird

3. Both (a) and (b)

4. pressure

5. surface of tyres

6. Polished marble surface

7. decrease

8. Increase friction

Explanation:

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