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#### Kinematics - Important Question Paper

11th Standard

Reg.No. :
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Physics

Time : 01:00:00 Hrs
Total Marks : 50

Part A

10 x 1 = 10
1. Two objects of masses m1 and m2 fall from the heights h1 and h2 respectively. The ratio of the magnitude of their momenta when they hit the ground is

(a)

$\sqrt { \frac { { h }_{ 1 } }{ { h }_{ 2 } } }$

(b)

$\sqrt { \frac { { { m }_{ 1 }h }_{ 1 } }{ { { m }_{ 2 }h }_{ 2 } } }$

(c)

$\frac { { m }_{ 1 } }{ { m }_{ 2 } } \sqrt { \frac { { h }_{ 1 } }{ { h }_{ 2 } } }$

(d)

$\frac { { m }_{ 1 } }{ { m }_{ 2 } }$

2. If a particle has negative velocity and negative acceleration, its speed

(a)

increases

(b)

decreases

(c)

remains same

(d)

zero

3. If the velocity is $\overrightarrow { v } =2\hat { i } +{ t }^{ 2 }\hat { j } -9\overrightarrow { k }$ then the magnitude of acceleration at t=0.5 s is

(a)

1 ms-2

(b)

2 ms-2

(c)

zero

(d)

-1 ms-2

4. If an object is dropped from the top of a building and it reaches the ground at t = 4 s, then the height of the building is (ignoring air resistance) (g = 9.8 ms-2)

(a)

77.3 m

(b)

78.4 m

(c)

80.5 m

(d)

79.2 m

5. A ball is projected vertically upwards with a velocity v. It comes back to ground in time t. Which v-t graph shows the motion correctly?

(a)

(b)

(c)

(d)

6. The angle between A i +j and B = i - j is

(a)

45°

(b)

90°

(c)

-45°

(d)

180°

7. The component of position vector $\overrightarrow { r }$ along x-axis will maximum value if

(a)

$\overrightarrow { r }$ is along the x - axis

(b)

$\overrightarrow { r }$ makes an angle of 45° with x - axis

(c)

$\overrightarrow { r }$  is along the y - axis

(d)

$\overrightarrow { r }$  is along - ve y - axis

8. Consider the quantities pressure, power, energy, impulse, charge. Out of these, the only vector quantity is

(a)

pressure

(b)

power

(c)

impulse

(d)

charge

9. The length of a vector is _______________

(a)

always a negative quantity

(b)

always a positive quantity

(c)

either positive or negative

(d)

denoted by '$\lambda$

10. $d\over dx$(x sin x) is equal to

(a)

sin x + cos x

(b)

sin x + x cos x

(c)

x - cos x

(d)

x cos x

11. Part B

6 x 2 = 12
12. Write note on function with example.

13. Write the relation between summation and integration.

14. Distinguish between average velocity and average speed.

15. An object is thrown vertically downward. What is the acceleration experienced by the object?

16. A gun is fired from a place which is at distance 1.2 km from a hill. The echo of the sound is heard back at the same place of firing after 8 second. Find the speed of sound.

17. A train 100 m long is moving with a speed of 60 km h-1. In how many seconds will it cross a bridge of 1 km long?

18. Part C

6 x 3 = 18
19. A projectile is fired horizontally with a velocity u. Obtain the expression for speed of the particle when it hits the ground.

20. A projectile is fired horizontally with a velocity u making an angle θ. Derive the expression for time of the flight.

21. Deduce the relation between angular acceleration and linear acceleration.

22. A girl travels along a straight road due east for the first half distance with speed v1 and the second half distance with speed v2. What is the average speed of the girl?

23. Find the distance travelled by the particle during the time t = 0 to t = 3 seconds from the figure.

24. If the speed ot.a particle is v = 10t2m/s. Find out distance covered from t = 2s to t = 5s.

25. Part D

2 x 5 = 10
26. A bus starting from rest moves with a uniform acceleration of 0.2 ms-2 for 3 minutes. Find the speed and distance travelled.

27. The velocity-time graph of an object moving along a straight line is as shown.

Calculate distance covered by object between t =0 to t = 3 and t = 0 to t = 6.