Force And Laws Of Motion Multiple Choice Questions

Force And Laws Of Motion Multiple Choice Questions

Direction: Choose the correct option for each question. There is only one correct response for each question.

Question 1. Choose the S.I. unit of force

1. cm/s
2. Newton
3. m/s
4. km/s

Answer. 2. Newton

Question 2. Which among the following are the types of inertia?

1. Rest
2. Motion
3. Direction
4. Volume

Answer. 4. Volume

Question 3. Which law of Newton states that ‘Every action has an equal and opposite reaction’?

1. The first law of motion
2. The second law of motion
3. Third law of motion
4. The fourth law of motion

Answer. 3. Third law of motion

Question 4. If a train starts suddenly in the forward direction, passengers standing on the train will fall ______.

1. Backwards
2. Forward
3. Sideways
4. Downwards

Answer. 1. Backwards

Question 5. The rate of change of momentum is equal to ______.

1. Work done
2. Acceleration
3. Speed
4. Force

Answer. 4. Force

Question 6. kg.m/s2 is the unit of _____.

1. Force
2.  Speed
3. Velocity
4. Acceleration

Answer. 1. Force

Question 7. A car is running with a force of 5 N. The weight of the car is 0.5 kg. What is the acceleration?

1. 5
2. 10
3. 15
4. 20

Answer. 2. 10

Question 8. The principle on which the jet engine works is _______.

1. Conservation of mass
2. Conservation of momentum
3. Newton’s first law of motion
4. Newton’s Second law of motion

Answer. 2. Conservation of momentum

Question 9. Inertia is a property of an object by which object is _______.

1. Not able to change its state of rest or uniform motion in a straight line
2. Not able to change its state of rest
3. Not able to change its direction of motion
4. Not able to change its state of uniform motion in a straight line

Answer. 1. Not able to change its state of rest or uniform motion in a straight line

Question 10. When a net force acts on an object, the object will be accelerated in the direction of force with acceleration proportional to ______ of the object.

1. Speed
2. Velocity
3. Acceleration
4. Force

Answer. 4. Force

Question 11. When an object undergoes ­acceleration, ___________.

1. Speed decreases
2. Speed increases
3. Force is acting on it
4. An object falls on the ground

Answer. 3. Force is acting on it

Question 12. Force can be defined from ______.

1. Newton’s first law of motion
2. Newton’s second law of motion
3. Newton’s third law of motion
4. Newton’s fourth law of motion

Answer. 1. Newton’s first law of motion

Question 13. If A and B are two objects of masses 10 kg and 20 kg respectively, then which among the following statements is correct?

1. A has more inertia than B
2. B has more inertia than A
3. A and B have the same inertia
4. None of the Above

Answer. 2. B has more inertia than A

Question 14. An object moves with constant acceleration if constant ______ is applied to the object.

1. Speed
2. Velocity
3. Force
4. Acceleration

Answer. 3. Force

Question 15. One Newton is the force equal to ______.

1. Gravity on 1 kg object
2. Mass of 1 kg and acceleration of 1 m/s2
3. Mass of 1 g and acceleration of 1 cm/s2
4. Gravity on 1 g object

Answer. 2. Mass of 1 kg and acceleration of 1 m/s2

Question 16. A man tosses a coin in a moving train and the coin falls behind him. It shows that the train is ______.

1. Accelerated
2. Retarded
3. Uniform
4. Moving in a circular track

Answer. 1. Accelerated

Question 17. A car of mass 20 kg is moving with an acceleration of 2 m/s2. What is the rate of change of momentum?

1. 10
2. 20
3. 30
4. 40

Answer. 4. 40

Question 18. An object is moving in a straight line in an acceleration motion. Choose the incorrect statement related to the statement.

1. Velocity keeps changing
2. Speed keeps changing
3. The object goes away from the earth
4. Force is always acting on an object

Answer. 3. Object goes away from the earth

Question 19. Rocket works on the principle of conservation of _______.

1. Speed
2. Velocity
3. Energy
4. Momentum

Answer. 4. Momentum

Question 20. As per the third law of motion, action, and reaction _______.

1. Always act on different objects in the opposite direction
2. Always act on the same body in the opposite direction
3. Always act on the same body in the same direction
4. Always act on the same body

Answer. 1. Always act on different objects in the opposite direction

Question 21. A goalkeeper holding the football pulls his hand backward because it helps the goalkeeper to ______.

1. Increase rate of change of momentum
2. Decrease rate of change of momentum
3. Exert larger force on football
4. Reduce the force exerted by the ball on the hand

Answer. 4. Reduce force exerted by the ball on the hand

Question 22. An athlete before doing a long jump, runs for some distance because ______.

1. Helps in applying a large force
2. Action and reaction force increases
3. Gives him a larger inertia of motion
4. Gains energy

Answer. 3. Gives him larger inertia of motion

Question 23. While riding a horse, the rider falls back when the horse starts because the ______.

1. The rider is afraid of falling back
2. The rider is taken back
3. The inertia of rest keeps the upper part of the body at rest while the lower part of the body moves forward with the horse
4. The inertia of rest keeps the lower part of the body at rest while the upper part of the body moves forward with the horse

Answer. 3. Inertia of rest keeps the upper part of the body at rest while the lower part of the body moves forward with the horse

Question 24. The property of inertia is more in ______.

1. Toy car
2. Car
3. Truck
4. Horse cart

Answer. 4. Horse cart

Question 25. A boy has a tennis ball and a football at rest. To move it, which among the following is correct

1. The same force is required for both
2. More force is required for a football ball
3. More force is required for a tennis ball
4. No force is required to move the balls

Answer. 2. More force is required for a football ball

Question 26. Which among the following is the equation for the second law of motion?

1. F = ma
2. F = mv
3. F = av
4. F = mav

Answer. 1. F = ma

Question 27. When a running car stops suddenly, the passenger tends to fall ______.

1. Forward
2. Backward
3. Sideways
4. Downside

Answer. 1. Forward

Question 28. ______ is an external cause that can move a still object to move and can stop a moving object.

1. Force
2. Speed
3. Velocity
4. Acceleration

Answer. 1. Force

Question 29. Force is a ______ quantity

1. Scalar
2. Vector
3. Both
4. None of the above

Answer. 2. Vector

Question 30. The inertia of an object depends on ______.

1. Force
2. Speed
3. Velocity
4. Mass

Answer. 4. Mass

Question 31. On applying equal and opposite forces on an object, the object will.

1. Move left
2. Move right
3. Doesn’t move
4. Move up

Answer. Doesn’t move

Question 32. The unit of Linear momentum is ______.

1. Ns
2. N/s
3. kg/s
4. g/s

Answer. 1. Ns

Question 33. The correct form of Newton’s second law of motion is ______.

1. F = \(\frac{\Delta p}{\Delta t}\)
2. F = \(m\left(\frac{\Delta v}{\Delta t}\right)\)
3. \(F=v\left(\frac{\Delta m}{\Delta t}\right)\)
4. F = mv

Answer. 1. F = \(\frac{\Delta p}{\Delta t}\)

Question 34. The C.G.S. unit of force is ______.

1. Newton
2. Dyne
3. kg/m
4. m/s

Answer. 2. Dyne

Question 35. Which law states that ’When an object is at rest it will remain at rest and if it is ­moving, it will continue to move in the same direction unless an external force is applied on it‘.

1. Newton’s first law of motion
2. Newton’s second law of motion
3. Newton’s third law of motion
4. Newton’s fourth law of motion

Answer. 1. Newton’s first law of motion

Question 36. Newton’s first law of motion is discussed through the definition of ______.

1. Inertia
2. Force
3. Speed
4. Acceleration

Answer. 

2. Force

3. Speed

Question 37. Which among the following are the units of Force?

1. kg/m
2. Newton
3. Dyne
4. m/s

Answer. 

3. Newton

4. Dyne

Question 38. Choose the correct statement:

1. If an object is at rest it will remain at rest until an external force is applied.
2. If an object is moving, it will continue to move until an external force is applied.
3. If an object is at rest it will remain at rest even after applying external force.
4. If an object is moving it will continue moving even after applying external force.

Answer.

1. If an object is at rest it will remain at rest until an external force is applied.

4. If an object is moving it will continue moving even after applying external force.

Question 39. Newton’s third law of motion states that ‘For every action, there is an equal and ______ reaction’.

1. Equal
2. less
3. Greater
4. Opposite

Answer.

1. Equal

4. Opposite

Question 40. Choose the incorrect equation:

1. 1 N = 1 kg.m/s²
2. F = m a
3. a = \(\frac{v}{t}\)
4. a = v – u

Answer. 

3. a = \(\frac{v}{t}\)

4. a = v – u

Question 41. Choose the correct statement:

1. The inertia of an object tends to cause the object to resist any change in its state of motion.
2. Inertia is a property of an object by the virtue of which an object is unable to change by itself the state of rest or uniform motion in a straight line.
3. Inertia is a property of an object by the virtue of which an object can change by itself the state of rest or uniform motion in a straight line.
4. The inertia of an object tends to cause the object to resist no change in its state of motion.

Answer.

1. The inertia of an object tends to cause the object to resist any change in its state of motion.
2. Inertia is a property of an object by the virtue of which an object is unable to change by itself the state of rest or uniform motion in a straight line.

Question 42. Choose the correct statement:

1. When a train starts suddenly, passengers standing on the train tend to fall backward.
2. When a train starts suddenly, passengers standing on the train tend to fall forward.
3. When a train stops suddenly, passengers standing on the train tend to fall forward.
4. When a train stops suddenly, passengers standing on the train tend to fall backward.

Answer. 

1. When a train starts suddenly, passengers standing on the train tend to fall backward.

3. When a train stops suddenly, passengers standing on the train tend to fall forward.

Question 43. Which of the following statements is correct for an object moving along a straight line in an accelerated motion?

1. Speed keeps changing
2. Velocity always change
3. It goes away from earth
4. Force is acting on it

Answer. 

1. Speed keeps changing

2. Velocity always changes

4. Force is acting on it

Question 44. Choose the incorrect statement. According to newton’s third law of motion, action, and reaction ______.

1. Acts on the same object in the same direction
2. Acts on different objects in the same direction
3. Acts on different objects in the opposite direction
4. Acts on the same object in a different direction

Answer. 

1. Acts on the same object in the same direction

2. Acts on different objects in the same direction

4. Acts on the same object in a different direction

Question 45. Choose the incorrect statement:

1. Rocket works on the principle of conservation of momentum.
2. Rocket works on the principle of conservation of mass.
3. Rocket works on the principle of conservation of energy.
4. Rocket works on the principle of conservation of velocity.

Answer. 

2. Rocket works on the principle of conservation of mass.

3. Rocket works on the principle of conservation of energy.

4. Rocket works on the principle of conservation of velocity.

Question 46. A body at rest breaks into two pieces of equal masses. The parts will move

1. in the same direction
2. along different lines
3. in opposite directions with equal speeds
4. in opposite directions with unequal speeds

Answer. 3. In opposite directions with equal speeds

Question 47. When a bus starts suddenly, the passengers standing inside lean backward. This is an example of

1. Newton’s first law of motion
2. Newton’s second law of motion
3. Newton’s third law of motion
4. Law of conservation of momentum

Answer. 1. Newton’s first law of motion

Question 48. A block of mass 2 kg is sliding with a constant velocity of 8 m/s on a frictionless horizontal surface. The force exerted on the horizontal surface is nearly

1. 20 N
2. 10 N
3. 40 N
4. 16 N

Answer. 1. 20 N

Question 49. A machine gun fires n bullets per second, each of mass m. If the speed of each bullet is u, then the force of recoil i

1. Mng
2. inv
3. moving
4. (Nov)/g

Answer. 2. inv

Question 50. A force of 5 N acts on a body of weight 9.8 N. What is the acceleration produced in m/s²

1. 0.51
2. 1.96
3. 5.00
4. 49.00

Answer. 3. 5.00

Question 51. In a game of tug of war, a condition of equilibrium exists. Both teams pull the rope with a force of 104 N. Tension in the rope is

1. 10⁴ N
2. 10⁸ N
3. 2 × 10⁴ N
4. zero

Answer. 1. 10⁴ N

Question 52. The action and reaction forces referred to in Newton’s third law of motion

1. must act on the same body
2. must act on different bodies
3. need not be equal in magnitude but must have the same line of action
4. must be equal in magnitude but need not have the same line of action

Answer. 2. must act on different bodies

Question 53. You are marooned on the frictionless horizontal plane and cannot exert any horizontal force by pushing against the surface. How can you get off?

1. By running on the plane
2. By jumping
3. By rolling your body on the surface
4. By sneezing or spitting

Answer. 3. By rolling your body on the surface

Question 54. Choose the wrong statement of the following

1. 1 kg wt = 9.8 N
2. Momentum is a vector quantity
3. Force is always conserved
4. Momentum is conserved in the absence of an external force

Answer. 3. Force is always conserved

Question 55. A long jumper runs before jumping because

1. he covers a greater distance
2. he maintains momentum conservation
3. he gains energy by running
4. he gains momentum

Answer. 4. he gains momentum

Question 56. A man is standing on a boat in still water. If he walks toward the shore the boat will

1. move away from the shore
2. remain stationary
3. move towards the shore
4. sink

Answer. 1. move away from the shore

Question 57. A body of mass 300 gm is at rest. What force in Newton will you have to apply to move it through 200 cm in 10 sec.?

1. Zero
2. 12 newton
3. 1.2 newton
4. 0.12 newton

Answer. 4. 0.12 Newton

Question 58. A boat of mass 3000 kg, initially at rest is pulled by a force of 1.8 × 104 Newton through a distance of 3 m. Assuming that the resistance due to water is negligible, the velocity of the boat is

1. 6 m/s
2. 8 m/s
3. 9 m/s
4. 11 m/s

Answer. 1. 6 m/s

Question 59. A certain force applied to mass m₁ gives it an acceleration of 15 m/s². The same force is applied on m₂ to give it an acceleration of 10 m/s², if the two masses are fixed together and the same force is applied to the combination, then the acceleration will be

1. 6 m/s²
2. 8 m/s²
3. 9 m/s²
4. 11 m/s²

Answer. 1. 6 m/s²

Question 60. A bullet of mass A and velocity B is fired into a block of wood of mass C. If loss of any mass and friction is neglected, then the velocity of the system must be

1. \(\frac{A B}{A+C}\)
2. \(\frac{A+C}{B+C}\)
3. \(\frac{A C}{B+C}\)
4. \(\frac{A+B}{A C}\)

Answer. 1. \(\frac{A B}{A+C}\)

Question 61. A driver accelerates his car first at the rate of 18 m/s2 and then at the rate of 12 m/s2. The ratio of the forces exerted by the engines respectively will be

1. 2 : 3
2. 1: 2
3. 2: 1
4. 3: 2

Answer. 1. 2 : 3

Question 62. A body of mass 5  kg undergoes a change in speed from 30 to 40 m/s. Its momentum would increase by

1. 50 kg m/s
2. 75 kg m/s
3. 150 kg m/s
4. 350 kg m/s

Answer. 1. 50 kg m/s

Question 63. A body of mass 5 kg undergoes a change in speed from 20 to 0.20 m/s. The momentum of the body would

1. increase by 99 kg m/s
2. decrease by 99 kg m/s
3. increase by 101 kg m/s
4. decrease by 101 kg m/s

Answer. 2. decrease by 99 kg m/s

Question 64. A body of mass 100 g is moving with a velocity of 15 m/s. The momentum associated with that ball will be

1. 0.5 kg m/s
2. 1.5 kg m/s
3. 2.5 kg m/s
4. 3.2 kg m/s

Answer. 2. 1.5 kg m/s

Question 65. A stationary ball weighing 0.25 kg acquires a speed of 10 m/s when hit by a hockey stick. The impulse imparted to the ball is

1. 2.5 N s
2. 2.0 N s
3. 1.5 N s
4. 0.5 N s

Answer. 1. 2.5 N s

Question 66. Momentum is a measure of

1. weight
2. mass
3. quantity of motion
4. velocity

Answer. 3. Quantity of motion

Question 67. It is difficult to walk on ice because of

1. absence of friction
2. absence of inertia
3. more inertia
4. more friction

Answer. 1. absence of friction

Question 68. A and B are two objects with mass 6 kg and 34 kg respectively. Then

1. A has more inertia than B
2. B has more inertia than A
3. A and B both have the same inertia
4. None of these

Answer. 2. B has more inertia than A

Question 69. When a body is stationary

1. there is no force acting on it
2. the forces acting on it are not in contact with it
3. the combination of forces acting on it balanced each other
4. the body is in a vacuum

Answer. 3. The combination of forces acting on it balanced each other

Question 70. Which of the following represents the SI unit of force?

1. dyne
2. gram-weight
3. newton
4. kilogram-weight

Answer. 3. newton

Question 71. When a constant force is applied to a body, it moves with a uniform

1. acceleration
2. velocity
3. speed
4. momentum

Answer. 1. acceleration

Question 72. Passengers standing in a bus are thrown outwards when the bus takes a sudden turn, due to

1. outward pull on them
2. inertia
3. change in momentum
4. change in acceleration

Answer. 2. inertia

Question 73. A body of mass M collides against a wall with velocity V and rebounds with the same speed. Its change of momentum is

1. zero
2. MV
3. 2 MV
4. –MV

Answer. 3. 2 MV

Question 74. Tires are made circular because

1. they can be inflated
2. they require less material
3. they look beautiful
4. they face less friction

Answer. 4. they face less friction

Question 75. If a 1 kg mass v-t graph is as shown, then which of the following is true?

1. force between A and B ≠ force between C and D
2. force between A and B = force between C and D
3. force between B and C = 1
4. data insufficient to calculate the force

Answer. 1. force between A and B ≠ force between C and D

Question 76. Two forces of 6N and 3N are acting on the two blocks of 2kg and 1kg kept on a frictionless floor. What is the force exerted on a 2kg block by a 1 kg block?

1. 1 N
2. 2 N
3. 4 N
4. 5 N

Answer. 3. 4 N

Question 77. Three masses of 1 kg, 6 kg, and 3 kg are connected with threads and are placed on the table as shown in the figure, What is the acceleration with which the system is moving? Take g = 10 m s^-2.

1. Zero
2. 1 m s^-2
3. 2 m s^-2
4. 3 m s^-2

Answer. 3. 2 m s^-2

Question 78. Two blocks of mass 4 kg and 2 kg are connected by a heavy string and placed on a rough horizontal plane. The 2 kg block is pulled with a constant force of F. The coefficient of friction between the blocks and the ground is 0.5. What is the value of F so that tension in the string is constant throughout during the motion of the blocks: (g = 10 m/s²)

1. 40 N
2. 30 N
3. 50 N
4. 60 N

Answer. 2. 30 N

Question 79. A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the figure. The force on the pulley by the clamp is given by

1. \(\sqrt{2}\) Mg
2. \(\sqrt{2}\) mg
3. \(\left(\sqrt{(M+m)^2+m^2}\right) g\)
4. \(\left(\sqrt{(M+m)^2+M^2}\right) g\)

Answer. 4. \(\left(\sqrt{(M+m)^2+M^2}\right) g\)

Force And Laws Of Motion Track Your Learning Questions and Answers

Question 1. If an object is still, it will remain still and if it is moving it will remain moving until an external force is applied. This is called ______.

1. Newton’s first law of motion
2. Newton’s second law of motion
3. Newton’s third law of motion
4. Newton’s fourth law of motion

Answer. 1. Newton’s first law of motion

Question 2. An object moving in a straight line will continue to move in the same direction until and unless some external force compels it to change the direction of motion. This is called ______.

1. Inertia of motion
2. Inertia of direction
3. Inertia of speed
4. Inertia of velocity

Answer. 2. Inertia of direction

Question 3. ______ is the external cause which tends to change the state of rest or the state of motion of an object.

1. Velocity
2. Speed
3. Force
4. Acceleration

Answer. 3. Force

Question 4. S.I. unit of inertia is ______.

1. t
2. kg
3. g
4. m

Answer. 2. kg

Question 5. _____ is the measure of inertia of a body at rest.

1. Mass
2. Time
3. Acceleration
4. Speed

Answer. 1. Mass

Force And Laws Of Motion Track Your Learning Questions and Answers

Question 1. C.G.S. unit of force is ______.

1. Newton
2. Dyne
3. kg
4. m/s

Answer. 2. Dyne

Question 2. Choose the correct equation

1. F = m a
2. F = m/a
3. F = m t
4. F = mv

Answer. 1. F = m a

Question 3. When a glass falls on the floor, it ______.

1. Jumps
2. Moves backward
3. Moves forward
4. Breaks

Answer. 4. Breaks

Question 4. S.I. unit of momentum is ______.

1. kgm/s
2. cm m/s
3. m/s
4. g cm/s

Answer. 1. kg m/s

Question 5. C.G.S. unit of momentum is ______.

1. kg m/s
2. cm m/s
3. m/s
4. g cm/s

Answer. 4. g cm/s

Force And Laws Of Motion Practice Exercises

Question 1. Which of the following statements is not correct for an object moving along a straight path in an accelerated motion?

1. Its speed keeps changing
2. Its velocity always changes
3. It always goes away from the earth
4. A force is always acting on it

Answer. 3. It always goes away from the earth

Question 2. According to the third law of motion, action and reaction

1. always act on the same body
2. always act on different bodies in opposite directions
3. have the same magnitude and directions
4. act on either body at normal to each other

Answer. 2. always act on different bodies in opposite directions

Question 3. A goalkeeper in a game of football pulls his hands backward after holding the ball shot at the goal. This enables the goalkeeper to

1. exert larger force on the ball
2. reduce the force exerted by the ball on the hands
3. increase the rate of change of momentum
4. decrease the rate of change of momentum

Answer. 2. reduce the force exerted by the ball on hands

Question 4. The inertia of an object tends to cause the object

1. to increase its speed
2. to decrease its speed
3. to resist any change in its state of motion
4. to decelerate due to friction

Answer. 3. To resist any change in its state of motion

Question 5. A passenger in a moving train tosses a coin which falls behind him. It means that the motion of the train is

1. accelerated
2. uniform
3. retarded
4. along circular tracks

Answer. 1. accelerated

Question 6. An object of mass 2 kg is sliding with a constant velocity of 4 ms-1 on a frictionless horizontal table. The force required to keep the object moving with the same velocity is

1. 32 N
2. 0 N
3. 2 N
4. 8 N

Answer. 2. 0 N

Question 7. Rocket works on the principle of conservation of

1. mass
2. energy
3. momentum
4. velocity

Answer. 3. momentum

Question 8. A water tanker filled up to 2/3 of its height is moving with a uniform speed. On sudden application of the brake, the water in the tank would

1. move backward
2. move forward
3. be unaffected
4. rise upwards

Answer. 2. move forward

Question 9. Which among the following is not an unbalanced force?

1. Stop a moving object
2. Two boys playing on a see-saw
3. Arm-wrestling competition
4. Pushing an object from both sides

Answer. 4. Pushing an object from both sides

Question 10. ________ is the force acting parallel to the surface of the contact.

1. Inertia
2. Balanced Force
3. Unbalanced Force
4. Frictional force

Answer. 2. Balanced Force

Question 11. If one object applies more force than the other one it is called _____ force.

1. Inertia
2. Balanced
3. Unbalanced
4. Linear

Answer. 3. Unbalanced