#### Laws of Motion Model Question Paper

11th Standard

Reg.No. :
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Physics

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. A vehicle is moving along the positive x direction, if sudden brake is applied, then

(a)

frictional force acting on the vehicle is along negative x direction

(b)

frictional force acting on the vehicle is along positive x direction

(c)

no frictional force acts on the vehicle

(d)

frictional force acts in downward direction

2. A book is at rest on the table which exerts a normal force on the book. If this force is considered as reaction force, what is the action force according to Newton's third law?

(a)

Gravitational force exerted by Earth on the book

(b)

Gravitational force exerted by the book on Earth

(c)

Normal force exerted by the book on the table

(d)

None of the above

3. A particle of mass m sliding on the smooth double inclined plane (shown in figure) will experience

(a)

greater acceleration along the path AB

(b)

greater acceleration along the path AC

(c)

same acceleration in both the paths

(d)

no acceleration in both the paths

4. A heavy iron rod of weight W is having its one end on the ground and the other on the shoulder of a man. The rod makes an angle ፀ with the horizontal. What is the weight experienced by the man?

(a)

W sin ፀ

(b)

W cos ፀ

(c)

W

(d)

$\frac { W }{ 2 }$

5. A ship of mass 3$\times$ 106 kg initially at rest is pulled by a force of 6 $\times$ 104 N through a distance of 4m. The speed of the ship is (Assume resistive of water is negligible)

(a)

1.5 m/s

(b)

20 m/s

(c)

0.5 m/s

(d)

0.4 m/s

6. 5 x 2 = 10
7. There is a limit beyond which the polishing of a surface increases frictional resistance rather than decreasing it why?

8. Why does a parachute descend slowly?

9. Can the coefficient of friction be more than one?

10. Why do passengers fall in backward direction when a bus suddenly starts moving from the rest position?

11. Give examples for inertia frames

12. 5 x 3 = 15
13. Explain various types of friction. Suggest a few methods to reduce friction.

14. What is the meaning by 'pseudo force'?

15. What are inertial frames?

16. A force of 10 N changes velocity of a body from 20 ms-1 to 40 ms=' in 8 seconds. How much force is required to bring about the same change in 4s.

17. A lift is moving down with an acceleration 5.0 ms-2. Calculate the percentage change in the weight of a person in the lift

18. 4 x 5 = 20
19. Briefly explain 'centrifugal force' with suitable examples.

20. Explain the need for banking of tracks.

21. Briefly explain what are all the forces act on a moving vehicle on a leveled circular road?

22. Explain why a gun recoils when a bullet is fired from it.