Olympiad Science - Force and Laws of Motion
Exam Duration: 45 Mins Total Questions : 30
How much mass (approximately) of a body one can hold, when a force of 1N is applied on it?
- (a)
100 mg
- (b)
100 g
- (c)
1kg
- (d)
10kg
What does the principle of conservation of linear momentum state?
- (a)
The linear momentum of a system cannot be changed.
- (b)
The linear momentum of a system cannot remain constant.
- (c)
The linear momentum of a system can be changed only if internal forces act.
- (d)
The linear momentum of a system can be changed only if external forces acts on it.
On which of the following do actionreaction forces act upon?
- (a)
Same body
- (b)
Different bodies
- (c)
Along different lines
- (d)
In the same direction
Consider a porter standing on a platform with a suitcase which presses his head with a force of 200 N. If this force is taken to be the action, from where is the reaction force exerted and to where is it directed?
- (a)
The head, on the suitcase
- (b)
The earth, on the suitcase
- (c)
The earth, on the porter
- (d)
The suitcase, on the earth
A force of 0.6 N acting on a particle increases its velocity from 5.0 m S-1 to 6.0 m S-1 in 2 s. What is the mass of the particle?
- (a)
1.2 kg
- (b)
2.2 kg
- (c)
4.2 kg
- (d)
6.2 kg
A body of mass 300 g at rest breaks into two parts due to internal forces. One part of mass 200 g is found to move at a velocity of 12 m S-1 towards east. Find the velocity of the other part.
- (a)
- 24 m S-1 towards west
- (b)
14 m S-1 towards east
- (c)
24 m S -1 towards north
- (d)
54 m S -1 towards south
Due to an impulse, the change in the momentum of a body is 1.8 kg m S-1. If the duration of the impulse is 0.2 s, then what is the force produced in it?
- (a)
9N
- (b)
8N
- (c)
7N
- (d)
6N
Two bodies collide at the same temperature. Which of the following is conserved?
(i) Velocity
(ii) Momentum
(iii) Kinetic energy
- (a)
Only (j) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ij) and (iij)
Vehicles are provided with shock absorbers. Which of the following laws of Newton given below explain this?
- (a)
The first law of motion
- (b)
The second law of motion
- (c)
The third law of motion
- (d)
All of the above
A ball of mass 100 g is moving with a velocity of 10m S-1. The force of the blow by the bat acts for 0.01 seconds. What is the force exerted on the ball by the bat?
- (a)
100 N
- (b)
200 N
- (c)
300 N
- (d)
400 N
A book is lying on a table. What is the angle between the book on the table and the weight of the book?
- (a)
0°
- (b)
45°
- (c)
90°
- (d)
180°
When a horse pulls a cart, what is the force that helps the horse move forward?
- (a)
The force exerted by the cart on the horse
- (b)
The force exerted by the ground on the horse
- (c)
The force exerted by the ground on the cart
- (d)
The force exerted by the horse on the cart
Which of the following physical quantities has the same units as that of impulse?
- (a)
Momentum
- (b)
Force
- (c)
Torque
- (d)
Couple
A cricket ball weighing 100 g and moving with a speed of 20 m s' strikes a bat and remains in contact with it for 0.1s. What is the force exerted by the ball on the bat?
- (a)
100 N
- (b)
-10 N
- (c)
-40 N
- (d)
1 N
A 10 N force applied on a body produces in it an acceleration of 2 m S-2. What is the mass of the body?
- (a)
20 kg
- (b)
0.2 kg
- (c)
5 kg
- (d)
200 g
If soldiers had the options to use guns of different weights but the bullets used are of a fixed weight, what would they prefer and why?
- (a)
Light guns, because handling them is easy
- (b)
Heavy guns, because they can be held firmly
- (c)
Heavy guns because they have less recoil
- (d)
Light guns, because they can be carried easily
The velocity-time graph of a ball moving on the surface of a floor is given below.
Calculate the force acting on the ball, if the mass of the ball is 200 g.
- (a)
1 N
- (b)
2 N
- (c)
5 N
- (d)
8 N
A motor car running at the rate of 7 m s -1 is stopped by applying the brakes after it travels 10m. Find the total resistance to the motion when the brakes are on.
- (a)
It is one-fourth of the weight of the car.
- (b)
It is two -thirds of the weight of the car.
- (c)
It is one -eighth of the weight of the car.
- (d)
It is four-fifths of the weight of the car.
A bullet of mass 60 g moving with a velocity of 500 m S-1 is brought to rest in 0.01 s. Find the impulse and the average force of the blow.
- (a)
- 3 N s,3 k N
- (b)
- 30 N s,- 3 k N
- (c)
- 50 N S,- 5 k N
- (d)
- 60 N s,- 6 k N
In a game of tug of wars, a condition of equilibrium exists. Both the teams pull the rope with a force of 104 N. Find the tension in the rope.
- (a)
0 N
- (b)
104 N
- (c)
105 N
- (d)
2 X 104 N
A truck and a car are moving with equal velocity. On applying brakes, if both decelerate at the same rate, what happens?
- (a)
The truck will cover less distance before stopping.
- (b)
The car will cover less distance before stopping.
- (c)
Both will cover equal distance
- (d)
None of the above
A bullet of mass20 g is fired from a rifle of 8 kg with an initial velocity of 100 m s-1. Find the final velocity of the recoil of the rifle.
- (a)
- 0.25 m s -1
- (b)
2.5 m s-1
- (c)
25 m s-1
- (d)
250 m s-1
A force acts on a body of mass 3 kg such that its velocity changes from 4 m S-1 to 10m S-1. Calculate the change in the momentum of the body.
- (a)
2 kg m S-1
- (b)
14 kg m S-1
- (c)
18 kg m S-1
- (d)
42 kg m S -1
Which of the following balls is easier to catch eventhough all of them are moving with the same velocity?
- (a)
Tennis ball
- (b)
Cricket ball
- (c)
Basket ball
- (d)
Both cricket and basket ball
A gun fires a bullet of mass 50 g with a velocity of 30 m S-1. Because of this, the gun is pushed back with a velocity of1 m S-1. What is the mass of the gun?
- (a)
3.5 kg
- (b)
30 kg
- (c)
1.5 kg
- (d)
20 kg
A scooter of mass 120 kg is moving with a uniform velocity of 108 km h-1. Calculate the force required to stop the vehicle in0.1 s.
- (a)
26000 N
- (b)
36000 N
- (c)
46000 N
- (d)
56000 N
A lift is moving down with a retardation of 5 m S-2. Calculate the percentage change in the weight of the person in the lift (g = 10m S-2).
- (a)
-25
- (b)
-50
- (c)
-75
- (d)
-100
A force of 200 N acts on a body of mass 2 kg for 10 s. Find the change in the momentum of the body.
- (a)
1000 N s
- (b)
250 N s
- (c)
500 N s
- (d)
2000 N s
Physical independence of force is a consequence of 'X' Identify 'X'.
- (a)
Newton's third law of motion
- (b)
Newton's second law of motion
- (c)
Newton's first law of motion
- (d)
All of the above
To which of the following laws is the principle of conservation of linear momentum equivalent?
- (a)
Newton's first law of motion
- (b)
Newton's second law of motion
- (c)
Newton's third law of motion
- (d)
Faraday's Laws
