Laws of Motion Test

Question 1
1 / -0

When a train stops suddenly, passengers in the running train feel an instant jerk in the forward direction because

A
The back of seat suddenly pushes the passengers forward

B
Inertia of rest stops the train and takes the body forward

C
Upper part of the body continues to be in the state of motion whereas the lower part of the body in contact with seat remains at rest

D
Nothing can be said due to insufficient data

Question 2
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A man getting down a running bus falls forward because

A
Due to inertia of rest, road is left behind and man reaches forward

B
Due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road

C
He leans forward as a matter of habit

D
Of the combined effect of all the three factors stated in

Question 3
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A particle is moving with a constant speed along a straight-line path. A force is not required to

A
Increase its speed

B
Decrease the momentum

C
Change the direction

D
Keep it moving with uniform velocity

Question 4
1 / -0

A bird weighs 2 kg and is inside a closed cage of 1 kg. If it starts flying, then what is the weight of the bird and cage assembly?

A
1.5 kg

B
2.5 kg

C
3 kg

D
4 kg

Question 5
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Newton's second law gives the measure of

A
Acceleration

B
Force

C
Momentum

D
Angular momentum

Question 6
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A force of 100 dynes acts on box of 5 gm for 10 sec. The velocity produced is

A
0.2 cm/sec

B
20 cm/sec

C
200 cm/sec

D
2000 cm/sec

Question 7
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A Diwali rocket is ejecting 0.05 kg of gases per second at a velocity of 400 m/sec. The accelerating force on the rocket is

A
20 dynes

B
20 N

C
22 dynes

D
1000 N

Question 8
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If the tension in the cable of 1000 kg elevator is 1000 kg weight, the elevator

A
Is accelerating upwards

B
Is accelerating downwards

C
May be at rest or accelerating

D
May be at rest or in uniform motion

Question 9
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A machine gun is mounted on a 2000 kg car on a horizontal frictionless surface. At some instant, the gun fires bullets of mass 10 gm with a velocity of 500 m/sec with respect to the car. The number of bullets fired per second is ten. The average thrust on the system is

A
550 N

B
50 N

C
250 N

D
250 dyne

Question 10
1 / -0

Gravels are dropped on a conveyor belt at the rate of 0.5 kg/sec. The extra force required in newtons to keep the belt moving at 2 m/sec is

A
1

B
3

C
5

D
0.5

Question 11
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When we jump out of a boat standing in water it moves

A
Forward

B
Backward

C
Sideways

D
None of the above

Question 12
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A ball of mass 150g starts moving with an acceleration of 20 m/\(s^2\). When hit by a force, which acts on it for 0.1 sec. The impulsive force is

A
0.5 N-s

B
0.1 N-s

C
0.3 N-s

D
1.2 N-s

Question 13
1 / -0

A bullet of mass 0.1 kg is fired with a speed of 100 m/sec; the mass of gun is 50 kg. The velocity of recoil is

A
0.2 m/sec

B
0.1 m/sec

C
0.5 m/sec

D
0.05 m/sec

Question 14
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Assertion: When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is always in forward direction.

Reason: The frictional force acts only when the bodies are in contact.

(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(B) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(C) If assertion is true but reason is false.

(D) If the assertion and reason both are false.

(E) If assertion is false but reason is true.

A
A

B
B

C
C

D
D

Question 15
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Assertion: No force is required by the body to remain in any state.

Reason: In uniform linear motion, acceleration has a finite value.

(A) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(B) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(C) If assertion is true but reason is false.

(D) If the assertion and reason both are false.

A
A

B
B

C
C

D
D

Question 16
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A block of weight 10 N resting on a horizontal surface. The coefficient of static friction between the block and the surface \(\mu_s\) = 0.4. A force of 3.5 N will keep the block in uniform motion, once it has been set in motion. A horizontal force of 3 N is applied to the block, and then the block will

A
Move over the surface with constant velocity

B
Move having accelerated motion over the surface

C
Not move

D
First it will move with a constant velocity for some time and then will have accelerated motion

Submit Test

Laws of Motion ...

Question 1

The back of seat suddenly pushes the passengers forward

Inertia of rest stops the train and takes the body forward

Upper part of the body continues to be in the state of motion whereas the lower part of the body in contact with seat remains at rest

Nothing can be said due to insufficient data

Question 2

Due to inertia of rest, road is left behind and man reaches forward

Due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road

He leans forward as a matter of habit

Of the combined effect of all the three factors stated in

Question 3

Increase its speed

Decrease the momentum

Change the direction

Keep it moving with uniform velocity

Question 4

1.5 kg

2.5 kg

3 kg

4 kg

Question 5

Acceleration

Force

Momentum

Angular momentum

Question 6

0.2 cm/sec

20 cm/sec

200 cm/sec

2000 cm/sec

Question 7

20 dynes

20 N

22 dynes

1000 N

Question 8

Is accelerating upwards

Is accelerating downwards

May be at rest or accelerating

May be at rest or in uniform motion

Question 9

550 N

50 N

250 N

250 dyne

Question 10

1

3

5

0.5

Question 11

Forward

Backward

Sideways

None of the above

Question 12

0.5 N-s

0.1 N-s

0.3 N-s

1.2 N-s

Question 13

0.2 m/sec

0.1 m/sec

0.5 m/sec

0.05 m/sec

Question 14

A

B

C

D

Question 15

A

B

C

D

Question 16

Move over the surface with constant velocity

Move having accelerated motion over the surface

Not move