Question practice 9 Force & Motion

                                                       

 MCQ Question 

1. What is the SI unit of force?

a) Newton
b) Joule
c) Watt
d) Pascal
Answer: a) Newton

2. Which of the following is not a vector quantity?

a) Force
b) Velocity
c) Displacement
d) Speed
Answer: d) Speed

3. The force that opposes the motion of a body is called:

a) Gravitational force
b) Frictional force
c) Normal force
d) Tension force
Answer: b) Frictional force

4. Which of the following quantities is a vector?

a) Distance
b) Speed
c) Velocity
d) Time
Answer: c) Velocity

5. The total distance traveled by an object in a given time divided by the time taken is called:

a) Velocity
b) Acceleration
c) Speed
d) Displacement
Answer: c) Speed

6. What is the acceleration of a body moving at uniform velocity?

a) 0
b) 10 m/s²
c) -10 m/s²
d) 9.8 m/s²
Answer: a) 0

7. The rate of change of velocity of an object is called:

a) Speed
b) Force
c) Acceleration
d) Displacement
Answer: c) Acceleration

8. What is the force required to give a mass of 2 kg an acceleration of 3 m/s²?

a) 6 N
b) 3 N
c) 5 N
d) 10 N
Answer: a) 6 N

9. Which of the following is not an example of motion?

a) A car moving on a straight road
b) A satellite orbiting the Earth
c) A book placed on a table
d) A ball thrown in the air
Answer: c) A book placed on a table

10. Which of the following forces is not a fundamental force?

a) Gravitational force
b) Electromagnetic force
c) Nuclear force
d) Frictional force
Answer: d) Frictional force

11. The acceleration due to gravity on Earth is approximately:

a) 9.8 m/s²
b) 10 m/s²
c) 8.8 m/s²
d) 9.6 m/s²
Answer: a) 9.8 m/s²

12. Which of the following is a non-contact force?

a) Friction
b) Tension
c) Gravitational force
d) Applied force
Answer: c) Gravitational force

13. What is the formula for calculating speed?

a) Speed = Distance × Time
b) Speed = Distance ÷ Time
c) Speed = Time ÷ Distance
d) Speed = Time × Force
Answer: b) Speed = Distance ÷ Time

14. Which of the following is not a vector quantity?

a) Displacement
b) Force
c) Velocity
d) Energy
Answer: d) Energy

15. What happens to the velocity of an object in free fall?

a) It remains constant
b) It increases
c) It decreases
d) It becomes zero
Answer: b) It increases

16. Which of the following is the unit of work?

a) Watt
b) Joule
c) Newton
d) Pascal
Answer: b) Joule

17. What is the momentum of an object with a mass of 2 kg moving at a velocity of 3 m/s?

a) 6 kg·m/s
b) 5 kg·m/s
c) 3 kg·m/s
d) 2 kg·m/s
Answer: a) 6 kg·m/s

18. What is the formula for calculating force?

a) F = m × v
b) F = m × a
c) F = m × g
d) F = m × t
Answer: b) F = m × a

19. Which of the following statements is correct regarding inertia?

a) Inertia is directly proportional to velocity
b) Inertia is the resistance to any change in motion
c) Inertia depends on the force applied
d) Inertia is the same for all objects
Answer: b) Inertia is the resistance to any change in motion

20. A body’s weight is defined as:

a) The force with which Earth attracts the body
b) The body’s resistance to motion
c) The body’s mass
d) The distance covered by the body
Answer: a) The force with which Earth attracts the body

21. What is the formula for calculating potential energy?

a) PE = m × a
b) PE = m × v
c) PE = m × g × h
d) PE = m × t
Answer: c) PE = m × g × h

22. Which of the following statements is true regarding acceleration?

a) Acceleration occurs only when a body is speeding up
b) Acceleration occurs only when a body is slowing down
c) Acceleration occurs when there is a change in velocity
d) Acceleration is always constant
Answer: c) Acceleration occurs when there is a change in velocity

23. The kinetic energy of an object depends on:

a) Its mass and speed
b) Its speed and height
c) Its mass and acceleration
d) Its mass and displacement
Answer: a) Its mass and speed

24. Which of the following forces is responsible for the motion of a satellite in orbit?

a) Gravitational force
b) Frictional force
c) Electrostatic force
d) Normal force
Answer: a) Gravitational force

25. Which of the following factors does not affect the frictional force?

a) The nature of the surface
b) The speed of the object
c) The weight of the object
d) The type of material
Answer: b) The speed of the object

26. Which law explains the relationship between the force applied to an object and the resulting acceleration?

a) Newton's First Law
b) Newton's Second Law
c) Newton's Third Law
d) Law of Universal Gravitation
Answer: b) Newton's Second Law

27. Which of the following is an example of an elastic collision?

a) A car crashing into a wall
b) A ball bouncing off the ground
c) A ball sticking to a wall
d) A bullet entering water
Answer: b) A ball bouncing off the ground

28. Which of the following is an example of mechanical energy?

a) Heat energy
b) Kinetic energy
c) Sound energy
d) Light energy
Answer: b) Kinetic energy

29. If a car moves with a uniform velocity, it means that:

a) Its acceleration is zero
b) Its acceleration is constant
c) It is moving in a straight line
d) It is moving with increasing velocity
Answer: a) Its acceleration is zero

30. In which of the following cases does no work get done?

a) A person lifting a box
b) A person pushing a box horizontally
c) A person holding a box stationary
d) A person running with a backpack
Answer: c) A person holding a box stationary

31. What is the unit of acceleration?

a) m/s
b) m/s²
c) N
d) kg
Answer: b) m/s²

32. If a body is at rest, which of the following statements is true?

a) The object has no force acting on it
b) The net force acting on the object is zero
c) The object’s velocity is zero
d) The object will remain stationary only if there is no friction
Answer: b) The net force acting on the object is zero

33. What is the formula for calculating work?

a) W = F × v
b) W = F × d
c) W = m × a
d) W = m × g
Answer: b) W = F × d

34. If the mass of an object is doubled, and its velocity is halved, what happens to its momentum?

a) Momentum remains the same
b) Momentum doubles
c) Momentum is halved
d) Momentum quadruples
Answer: a) Momentum remains the same

35. What happens to an object's velocity when it moves with uniform acceleration?

a) It increases linearly
b) It remains constant
c) It decreases linearly
d) It oscillates
Answer: a) It increases linearly

36. Which of the following forces is not considered as a contact force?

a) Gravitational force
b) Normal force
c) Frictional force
d) Tension force
Answer: a) Gravitational force

37. Which of the following is not a vector quantity?

a) Velocity
b) Acceleration
c) Force
d) Work
Answer: d) Work

38. The momentum of an object is:

a) The product of its mass and velocity
b) The product of its mass and speed
c) The square of its mass
d) The square of its speed
Answer: a) The product of its mass and velocity

39. When an object is in free fall, the only force acting on it is:

a) Gravitational force
b) Friction
c) Tension
d) Normal force
Answer: a) Gravitational force

40. Which of the following is an example of a non-contact force?

a) Frictional force
b) Gravitational force
c) Applied force
d) Normal force
Answer: b) Gravitational force

41. What is the energy possessed by a body due to its position?

a) Kinetic energy
b) Potential energy
c) Thermal energy
d) Chemical energy
Answer: b) Potential energy

42. Which of the following will cause an object to accelerate?

a) A change in velocity
b) A change in speed
c) A change in direction
d) All of the above
Answer: d) All of the above

43. What is the unit of work in the SI system?

a) Watt
b) Joule
c) Newton
d) Kilogram
Answer: b) Joule

44. Which of the following forces is always attractive?

a) Gravitational force
b) Electromagnetic force
c) Tension force
d) Normal force
Answer: a) Gravitational force

45. Which of the following equations represents Newton's Second Law of Motion?

a) F = ma
b) F = m × g
c) F = v × t
d) F = m × v
Answer: a) F = ma

46. Which of the following types of collisions conserves both kinetic energy and momentum?

a) Perfectly inelastic collision
b) Elastic collision
c) Inelastic collision
d) All of the above
Answer: b) Elastic collision

47. What is the acceleration of an object in free fall near the Earth's surface?

a) 9.8 m/s²
b) 10 m/s²
c) 9.8 N
d) 10 N
Answer: a) 9.8 m/s²

48. Which of the following is true about Newton's First Law of Motion?

a) An object in motion will stay in motion unless acted upon by an unbalanced force
b) The velocity of an object always changes with time
c) The acceleration of an object is zero unless a force acts on it
d) The object will eventually stop unless a force is applied
Answer: a) An object in motion will stay in motion unless acted upon by an unbalanced force

49. Which of the following is true about force?

a) It is a vector quantity
b) It is a scalar quantity
c) It only depends on mass
d) It only depends on velocity
Answer: a) It is a vector quantity

50. What is the unit of power in the SI system?

a) Newton
b) Joule
c) Watt
d) Kilogram
Answer: c) Watt

51. The force acting on a body at rest is:

a) Zero
b) A constant force
c) A variable force
d) None of the above
Answer: a) Zero

52. What is the force that keeps an object in circular motion?

a) Friction
b) Gravitational force
c) Centripetal force
d) Centrifugal force
Answer: c) Centripetal force

53. The velocity of an object can be described as:

a) The rate at which an object changes its position
b) The rate at which an object changes its speed
c) The distance covered per unit time
d) The displacement covered per unit time
Answer: d) The displacement covered per unit time

54. Which of the following statements is correct about acceleration?

a) Acceleration is the rate of change of velocity
b) Acceleration is the rate of change of distance
c) Acceleration is the rate of change of speed
d) Acceleration is the rate of change of force
Answer: a) Acceleration is the rate of change of velocity

55. What is the work done when a force of 10 N is applied over a distance of 5 meters in the direction of the force?

a) 15 J
b) 50 J
c) 5 J
d) 100 J
Answer: b) 50 J

56. Which of the following is the correct formula for kinetic energy?

a) KE = m × v
b) KE = 1/2 m × v²
c) KE = 1/2 m × a²
d) KE = m × g × h
Answer: b) KE = 1/2 m × v²

57. Which of the following is a non-contact force?

a) Friction
b) Applied force
c) Gravitational force
d) Tension
Answer: c) Gravitational force

58. The principle of conservation of momentum states that:

a) The total momentum before and after a collision remains the same
b) The total energy before and after a collision remains the same
c) Momentum is always conserved in every process
d) All objects will come to rest eventually
Answer: a) The total momentum before and after a collision remains the same

59. Which of the following is true for an object in free fall?

a) Its speed increases with time
b) Its velocity remains constant
c) The gravitational force on the object is zero
d) The object’s acceleration decreases with time
Answer: a) Its speed increases with time

60. If the force acting on a body is zero, the body will:

a) Change its motion
b) Stay at rest
c) Continue moving with constant velocity
d) Accelerate
Answer: c) Continue moving with constant velocity

61. The momentum of an object is equal to:

a) Mass × Velocity
b) Force × Time
c) Velocity × Acceleration
d) Mass × Acceleration
Answer: a) Mass × Velocity

62. What happens to the speed of an object when the net force acting on it is zero?

a) It remains constant
b) It increases
c) It decreases
d) It becomes zero
Answer: a) It remains constant

63. Which of the following is the unit of energy?

a) Joule
b) Watt
c) Newton
d) Meter
Answer: a) Joule

64. The resistance of an object to a change in its state of motion is called:

a) Force
b) Inertia
c) Work
d) Momentum
Answer: b) Inertia

65. In which of the following cases will the work done be zero?

a) Lifting a weight vertically
b) Pushing a box across the floor
c) An object moving at constant speed on a frictionless surface
d) Pulling an object upwards
Answer: c) An object moving at constant speed on a frictionless surface

66. The force required to change the motion of an object depends on:

a) The mass of the object
b) The velocity of the object
c) The distance traveled by the object
d) The time taken for the motion
Answer: a) The mass of the object

67. Which of the following is true about Newton’s Third Law of Motion?

a) For every action, there is an equal and opposite reaction
b) Force equals mass times acceleration
c) Objects remain in motion unless acted upon by an external force
d) Velocity is constant unless a force acts upon it
Answer: a) For every action, there is an equal and opposite reaction

68. If the force acting on an object is increased, what happens to its acceleration?

a) It decreases
b) It increases
c) It remains constant
d) It becomes zero
Answer: b) It increases

69. If a car's speed doubles, how does its kinetic energy change?

a) It remains the same
b) It doubles
c) It increases by a factor of four
d) It decreases by a factor of four
Answer: c) It increases by a factor of four

70. The force of attraction between two objects depends on:

a) Their masses and the distance between them
b) The velocity of the objects
c) The direction of the objects
d) The shape of the objects
Answer: a) Their masses and the distance between them

71. What is the effect of increasing the mass of an object on its acceleration for a given force?

a) The acceleration increases
b) The acceleration decreases
c) The acceleration remains the same
d) The object stops moving
Answer: b) The acceleration decreases

72. Which of the following is the best description of an object’s inertia?

a) The object’s tendency to change its velocity
b) The object’s ability to resist changes in its motion
c) The object’s ability to do work
d) The object’s tendency to accelerate
Answer: b) The object’s ability to resist changes in its motion

73. If an object is moving in a circular path, the force that causes this motion is:

a) Centripetal force
b) Gravitational force
c) Frictional force
d) Tension force
Answer: a) Centripetal force

74. Which of the following is not a scalar quantity?

a) Speed
b) Distance
c) Force
d) Time
Answer: c) Force

75. When a car accelerates, its:

a) Velocity increases
b) Velocity decreases
c) Distance traveled remains the same
d) Speed remains constant
Answer: a) Velocity increases

76. The gravitational force between two objects is directly proportional to:

a) The product of their masses
b) The sum of their masses
c) The square of the distance between them
d) The difference in their masses
Answer: a) The product of their masses

77. Which of the following can be changed by applying force?

a) Speed
b) Velocity
c) Direction
d) All of the above
Answer: d) All of the above

78. What is the effect of increasing the velocity of an object on its kinetic energy?

a) It decreases
b) It increases
c) It remains constant
d) It becomes zero
Answer: b) It increases

79. The SI unit of force is:

a) Newton
b) Joule
c) Watt
d) Kilogram
Answer: a) Newton

80. Which of the following is true for an object moving with constant velocity?

a) The net force acting on it is zero
b) The velocity is increasing
c) The object is accelerating
d) The object is decelerating
Answer: a) The net force acting on it is zero

81. What is the change in momentum of an object if the net force acting on it is zero?

a) Momentum increases
b) Momentum decreases
c) Momentum remains constant
d) Momentum becomes zero
Answer: c) Momentum remains constant

82. Which of the following is true about the motion of an object when a force is applied at an angle to the object?

a) The object moves in the direction of the applied force
b) The object moves in a circular path
c) The object moves in a straight line
d) The object moves in the opposite direction of the applied force
Answer: a) The object moves in the direction of the applied force

83. If a car moves at constant speed on a circular track, which force acts on the car?

a) Centripetal force
b) Frictional force
c) Gravitational force
d) All of the above
Answer: d) All of the above

84. What is the formula for calculating potential energy?

a) PE = 1/2 m × v²
b) PE = m × g × h
c) PE = m × v
d) PE = F × d
Answer: b) PE = m × g × h

85. Which of the following does not change the velocity of an object?

a) A constant force
b) A frictional force
c) A force in the direction of motion
d) A force perpendicular to the direction of motion
Answer: d) A force perpendicular to the direction of motion

86. Which of the following is true about an object in uniform circular motion?

a) Its speed is constant, but its velocity changes
b) Its velocity is constant, but its speed changes
c) Both speed and velocity are constant
d) Both speed and velocity are changing
Answer: a) Its speed is constant, but its velocity changes

87. The law of conservation of energy states that:

a) Energy cannot be created or destroyed, only transformed
b) Energy is created and destroyed in equal amounts
c) Energy can only be created
d) Energy can only be destroyed
Answer: a) Energy cannot be created or destroyed, only transformed

88. The momentum of an object changes when:

a) Its mass changes
b) Its velocity changes
c) Both its mass and velocity change
d) None of the above
Answer: b) Its velocity changes

89. What is the gravitational force acting on a 10 kg object on Earth? (Assume g = 9.8 m/s²)

a) 98 N
b) 10 N
c) 9.8 N
d) 100 N
Answer: a) 98 N

90. What is the effect of friction on motion?

a) It increases motion
b) It opposes motion
c) It has no effect on motion
d) It accelerates motion
Answer: b) It opposes motion

91. The force of friction depends on:

a) The roughness of the surface
b) The mass of the object
c) The nature of the surfaces in contact
d) All of the above
Answer: d) All of the above

92. Which of the following is an example of an unbalanced force?

a) A book resting on a table
b) A car moving at constant speed
c) A car accelerating
d) A person walking at constant speed
Answer: c) A car accelerating

93. The momentum of an object is a product of:

a) Mass and acceleration
b) Mass and velocity
c) Force and time
d) Speed and distance
Answer: b) Mass and velocity

94. Which of the following statements is true about an object moving with uniform velocity?

a) The object has no acceleration
b) The object has constant speed
c) The object moves in a straight line
d) All of the above
Answer: d) All of the above

95. If a person jumps off a boat and the boat moves in the opposite direction, this is an example of:

a) Newton's First Law
b) Newton's Second Law
c) Newton's Third Law
d) The law of conservation of momentum
Answer: c) Newton's Third Law

96. The momentum of an object is defined as:

a) Mass times acceleration
b) Mass times velocity
c) Mass times velocity squared
d) Mass divided by velocity
Answer: b) Mass times velocity

97. What is the SI unit of work?

a) Joule
b) Newton
c) Watt
d) Pascal
Answer: a) Joule

98. Which of the following is a vector quantity?

a) Speed
b) Distance
c) Displacement
d) Energy
Answer: c) Displacement

99. A body is said to be in free fall when:

a) It is moving upward
b) The force of gravity is the only force acting on it
c) Air resistance is greater than gravity
d) It is not moving
Answer: b) The force of gravity is the only force acting on it

100. The acceleration due to gravity is:

a) Constant at all points on Earth
b) Greatest at the poles
c) Zero at the equator
d) Equal to zero everywhere
Answer: b) Greatest at the poles

101. What happens to an object’s potential energy when it is lifted to a higher height?

a) It decreases
b) It increases
c) It remains the same
d) It becomes zero
Answer: b) It increases

102. In a uniform circular motion, the object’s velocity is:

a) Constant
b) Changing in magnitude but not direction
c) Changing in direction
d) Changing in both magnitude and direction
Answer: c) Changing in direction

103. Which of the following statements is correct?

a) An object moving with a constant velocity must have zero acceleration
b) An object moving with constant acceleration must have constant speed
c) An object with a constant force acting on it must have constant speed
d) None of the above
Answer: a) An object moving with a constant velocity must have zero acceleration

104. Which of the following is the correct expression for momentum?

a) p = m × v
b) p = m × a
c) p = F × t
d) p = m × g
Answer: a) p = m × v

105. The rate at which work is done is called:

a) Energy
b) Power
c) Force
d) Velocity
Answer: b) Power

106. What is the relationship between mass and weight?

a) Mass is directly proportional to weight
b) Mass is inversely proportional to weight
c) Mass is equal to weight
d) Mass and weight are unrelated
Answer: a) Mass is directly proportional to weight

107. A car accelerates from rest at a constant rate. Which of the following is true about its velocity?

a) It remains constant
b) It decreases
c) It increases
d) It becomes zero
Answer: c) It increases

108. Which of the following factors does not affect the frictional force between two surfaces?

a) The roughness of the surfaces
b) The weight of the object
c) The shape of the object
d) The temperature of the surfaces
Answer: c) The shape of the object

109. The work done by a force is zero when:

a) The object is moving at constant velocity
b) The object moves in the direction of the force
c) The object moves perpendicular to the direction of the force
d) The object moves with increasing velocity
Answer: c) The object moves perpendicular to the direction of the force

110. What is the formula for calculating work?

a) W = F × d
b) W = F × v
c) W = m × g × h
d) W = p × t
Answer: a) W = F × d

111. If an object’s acceleration is zero, it is:

a) Moving at a constant speed
b) At rest
c) Accelerating
d) Both a and b
Answer: d) Both a and b

112. A body moves in a straight line with uniform acceleration. The relationship between velocity, acceleration, and time is given by:

a) v = u + at
b) v = u - at
c) v = u × t
d) v = u × a
Answer: a) v = u + at

113. Which of the following is an example of balanced forces?

a) A book resting on a table
b) A car accelerating
c) A falling apple
d) A person walking
Answer: a) A book resting on a table

114. In which direction does the force of friction act?

a) In the same direction as motion
b) In the opposite direction to the motion
c) In a direction perpendicular to the motion
d) It does not act on objects
Answer: b) In the opposite direction to the motion

115. The net force on an object is the vector sum of:

a) All forces acting on it
b) The mass and the velocity of the object
c) The gravitational force and normal force
d) The force applied and the frictional force
Answer: a) All forces acting on it

116. Which of the following is the correct formula for acceleration?

a) a = (v - u)/t
b) a = (v + u)/t
c) a = u × t
d) a = v × t
Answer: a) a = (v - u)/t

117. Which of the following is not a type of force?

a) Gravitational force
b) Electromagnetic force
c) Magnetic force
d) Color force
Answer: d) Color force

118. The change in momentum of an object is equal to:

a) Mass × velocity
b) Force × time
c) Mass × acceleration
d) Force × distance
Answer: b) Force × time

119. Which of the following best describes inertia?

a) An object’s resistance to changes in its state of motion
b) An object’s tendency to move faster
c) An object’s ability to do work
d) An object’s ability to stop
Answer: a) An object’s resistance to changes in its state of motion

120. The SI unit of momentum is:

a) kg·m/s
b) N·s
c) m/s²
d) kg
Answer: a) kg·m/s

Short answer question

Define force.

State Newton’s First Law of Motion.

What is the difference between speed and velocity?

What is acceleration?

What does Newton’s Second Law of Motion state?

What is inertia?

Explain the law of conservation of momentum.

What is friction?

What is the unit of force in the SI system?

What is the formula for calculating work?

State Newton’s Third Law of Motion.

What is momentum?

How does gravity affect the motion of objects?

What is the relationship between force and acceleration?

What is meant by the term "uniform motion"?

What is the difference between mass and weight?

Explain the concept of centripetal force.

What is the effect of air resistance on a falling object?

What is the work-energy theorem?

How is power defined?

What is the formula for calculating acceleration?

Define uniform circular motion.

What is the role of a force in changing the velocity of an object?

State the principle of conservation of energy.

What is the difference between contact forces and non-contact forces?

Define gravitational potential energy.

What is the formula for gravitational potential energy?

What is meant by the term "terminal velocity"?

What is meant by the term "resultant force"?

Define mechanical energy.

What is the difference between kinetic energy and potential energy?

How does friction affect motion?

What is the relationship between work and energy?

Define impulse.

How does the mass of an object affect its momentum?

What is the SI unit of momentum?

Define power in terms of work and time.

What is meant by the term "conservative force"?

How does air resistance affect the speed of a falling object?

Define a vector quantity and give two examples.

Define a scalar quantity and give two examples.

What is the SI unit of velocity?

What is the difference between speed and velocity?

What is the principle of superposition of forces?

What does the term "balanced force" mean?

How does acceleration due to gravity vary at different altitudes?

What is the effect of an unbalanced force on an object?

What is meant by "Newton's Law of Universal Gravitation"?

What is the difference between static friction and kinetic friction?

What is meant by the term "centrifugal force"?

What is a free body diagram?

Define the term "work done" in physics.

What is the relationship between force, mass, and acceleration?

How does the weight of an object change with location?

Define the term "motion".

What is the difference between uniform motion and non-uniform motion?

What is the principle of action and reaction in Newton’s Third Law?

Define "conservation of momentum".

What is the difference between positive and negative acceleration?

What is the SI unit of energy?

Define "law of inertia".

What is the role of friction in everyday life?

How is acceleration calculated?

What are the effects of balanced forces on an object?

What is the effect of a force applied at an angle to the direction of motion?

What is meant by "net force"?

What is the unit of velocity in the SI system?

What is the importance of friction in motion?

How does mass affect the acceleration of an object when a force is applied?

What is the effect of air resistance on a projectile's motion?

What does the equation F = ma represent?

Define elastic collision.

Define inelastic collision.

What is the significance of a distance-time graph?

What is the significance of a velocity-time graph?

What is meant by "acceleration due to gravity"?

What is the difference between a scalar and vector quantity?

How does the motion of an object change if no force is applied?

What happens to the motion of an object when forces are balanced?

How do changes in velocity affect the momentum of an object?

 Long Answer question

Explain Newton’s Three Laws of Motion with examples.

Describe the concept of momentum. Derive its formula and explain the law of conservation of momentum.

Discuss the various types of forces in detail. Explain contact and non-contact forces with examples.

State and explain the principle of work and energy. Derive the formula for work done and explain the concept of kinetic and potential energy.

Explain the concept of friction. Discuss its types, advantages, and disadvantages. How can friction be reduced or increased?

Explain the motion of a body under the influence of gravity. Derive the equations of motion for an object in free fall and explain the concept of terminal velocity.

Describe the concept of uniform circular motion. Derive the expression for centripetal force and explain its significance.

Define and explain the concept of acceleration. Derive the equation of motion for uniformly accelerated motion and explain the significance of each term.

Explain the concept of energy and its different forms. Discuss the law of conservation of energy with suitable examples.

Discuss the role of inertia in the motion of objects. Explain how inertia is related to mass and provide examples to illustrate the concept.

What is the relationship between force and acceleration according to Newton’s Second Law of Motion? Explain the law with an example and derive the equation F = ma.

Describe the work-energy theorem. How is work related to kinetic energy, and how can this relationship be used to solve problems involving motion?

Discuss the concept of power. Derive the formula for power and explain its relation to work and time. Provide examples of power consumption in everyday life.

Explain the principle of conservation of momentum in a closed system. Discuss how this principle is applied in collisions and provide examples of elastic and inelastic collisions.

Explain the difference between mass and weight. How does gravitational acceleration affect the weight of an object? Discuss how weight varies with location on Earth.

What are the different types of motion? Explain the characteristics of linear motion, circular motion, and rotational motion with examples.

Describe the effect of air resistance on the motion of an object. How does air resistance vary with the velocity of an object, and how does it affect the speed of falling objects?

What is meant by the term "uniform motion"? Explain with examples and discuss the differences between uniform and non-uniform motion.

Discuss the concept of centripetal force. Derive the expression for centripetal force acting on an object moving in a circular path. Explain the effect of increasing the speed and radius on the centripetal force.

What is the role of gravitational force in the motion of celestial bodies? Explain the law of universal gravitation and discuss its significance in the motion of planets, satellites, and artificial objects in space.

Explain how friction can be reduced in machines. Discuss methods such as lubrication, use of ball bearings, and reducing the roughness of surfaces in detail.

What is the relationship between the force applied to an object and its motion? Discuss how the net force affects the acceleration of an object according to Newton's Second Law of Motion.

Explain the concept of angular velocity and angular acceleration. Derive the equations for angular motion and explain their applications in rotational systems.

Describe the different types of energy, such as kinetic, potential, thermal, and chemical energy. How do these energies convert from one form to another in mechanical systems?

Discuss the importance of balanced forces and unbalanced forces in the motion of an object. How do these forces affect the speed, direction, and shape of an object’s motion?

Explain the concept of a free body diagram. How can free body diagrams be used to solve problems related to the forces acting on a body in different types of motion?

Discuss the role of air resistance and how it impacts the motion of objects such as falling bodies, skydivers, and projectiles. How does air resistance affect the terminal velocity?

What is the difference between elastic and inelastic collisions? Explain the conservation of momentum and energy in both types of collisions with examples.

Describe how Newton’s Third Law of Motion applies to everyday activities. Explain action and reaction forces with examples like walking, sitting in a chair, or swimming.

Explain the significance of the work-energy principle in understanding the motion of objects. Derive the equation for kinetic energy and discuss its practical applications in real-world scenarios.

Explain the difference between uniform acceleration and non-uniform acceleration. Provide examples to illustrate both types of acceleration.

Discuss the factors affecting the force of friction. How can friction be increased or decreased? Provide examples from real life.

Describe the concept of projectile motion. Derive the equations of motion for a projectile and explain the factors affecting the range and time of flight.

Explain the concept of free fall. Derive the equations of motion for an object in free fall and discuss the effect of air resistance on free-falling bodies.

Explain the relationship between speed, velocity, and acceleration. How do these quantities relate to one another in uniformly accelerated motion?

Describe the process of energy conversion in machines. Explain how mechanical energy is converted into other forms of energy during operation.

What is the role of torque in rotational motion? Derive the equation for torque and explain how it affects the angular acceleration of an object.

Explain the concept of simple harmonic motion (SHM). Derive the equation of motion for SHM and discuss its characteristics.

Discuss the principle of moments. Derive the condition for equilibrium and explain how this principle is applied in various mechanical systems.

Explain the concept of the law of conservation of energy in the context of roller coasters. Discuss how potential and kinetic energy transform as the roller coaster moves along its track.

What is the difference between elastic and plastic deformation? Discuss the factors affecting each type of deformation and provide examples of materials exhibiting both.

Explain the significance of the gravitational potential energy of an object. Derive the formula for gravitational potential energy and discuss its applications.

Describe the concept of inertial and non-inertial frames of reference. Explain how Newton's laws of motion apply in each of these frames.

What are the effects of centrifugal and centripetal forces on objects moving in circular paths? Discuss how these forces are balanced in a rotating system.

Describe the motion of an object under the influence of both gravitational and frictional forces. Derive the equations of motion for such a scenario.

What is the significance of the coefficient of friction in determining the amount of frictional force? Discuss the factors affecting this coefficient and how it can be measured.

Explain the concept of a harmonic oscillator. Derive the equation for the period of a simple harmonic oscillator and discuss factors that affect it.

Describe the process of energy loss due to friction. How can engineers minimize energy loss in machines and vehicles? Provide examples.

Discuss the concept of angular momentum. Derive the expression for angular momentum and explain the conservation of angular momentum in isolated systems.

Explain the relationship between linear and angular velocity. How are these quantities related in rotational motion, and how do they affect the motion of rotating objects?

Explain the principle of conservation of mechanical energy in the case of a pendulum. Derive the potential and kinetic energy equations and explain the motion.

Describe the motion of an object subjected to varying forces. Explain how Newton’s Second Law applies to objects under non-uniform force fields.

Discuss the effects of different types of waves (longitudinal and transverse) on the motion of particles. Provide examples of each and explain their behavior.

What is the difference between velocity and speed? How does the velocity of an object change during motion in different directions?

Describe the working principle of hydraulic systems. How does the force applied in a hydraulic system relate to the output force?

What are the main factors influencing the rate of change of velocity (acceleration) of an object? Discuss how mass, force, and other factors contribute to the acceleration.

Explain the concept of elasticity. Discuss Hooke’s Law and the relationship between stress and strain in elastic materials.

Discuss the concept of linear momentum. How is momentum conserved in a collision, and how does this principle apply to real-world collisions?

Explain the significance of the principle of relativity in mechanics. How does it affect our understanding of motion at different velocities?

What is the relationship between kinetic energy and work done on an object? Explain how kinetic energy changes when work is applied to an object.

Give reason

Give reason why a body moving with uniform velocity is not under the influence of force.

Give reason why a car slows down when brakes are applied.

Give reason why a feather falls slower than a stone when dropped from the same height.

Give reason why a body in motion tends to continue in motion unless acted upon by an external force.

Give reason why a person leaning forward in a car while it takes a sharp turn is due to inertia.

Give reason why an object of greater mass requires more force to change its state of motion than an object of smaller mass.

Give reason why the momentum of a moving object is greater than that of a stationary object of the same mass.

Give reason why the weight of an object is different on the surface of the Earth and the Moon.

Give reason why a parachute slows down the fall of a person.

Give reason why a rocket can move in space despite there being no air or medium.

Give reason why it is easier to push a box on a smooth surface than on a rough surface.

Give reason why a car requires more energy to accelerate when it is fully loaded than when it is empty.

Give reason why the action and reaction forces are equal and opposite but do not cancel each other out.

Give reason why the velocity of an object in free fall increases as it falls.

Give reason why the force of friction increases with an increase in the roughness of the surfaces in contact.

Give reason why a body in uniform circular motion experiences a centripetal force.

Give reason why a gun recoils when it is fired.

Give reason why the mass of an object is constant but its weight changes with altitude.

Give reason why a heavier object falls faster than a lighter object in a vacuum.

Give reason why a running athlete leans forward.

Give reason why a satellite orbiting the Earth moves in a circular path.

Give reason why objects of different masses fall at the same rate in the absence of air resistance.

Give reason why astronauts experience weightlessness in space.

Give reason why a force is required to stop a moving object.

Give reason why water can be split by applying a force in a direction parallel to the surface of the water.

Give reason why the force of gravity is weaker at the equator than at the poles.

Give reason why an object in motion maintains its motion unless an external force acts upon it.

Give reason why it is difficult to push a car from rest compared to when it is already moving.

Give reason why a car speeds up when it accelerates but slows down when brakes are applied.

Give reason why the speed of a moving object increases when an unbalanced force is applied to it.

Give reason why a spaceship can travel in space without any propulsion system after reaching its desired speed.

Give reason why a stone thrown upwards slows down as it rises.

Give reason why a body moving in a circle needs a continuous force to keep it in circular motion.

Give reason why an object falls with an increasing speed if no air resistance is present.

Give reason why a light object falls slower than a heavy object when air resistance is present.

Give reason why the gravitational force between two bodies decreases as the distance between them increases.

Give reason why an object in motion remains in motion with the same speed and in the same direction unless acted upon by an external force.

Give reason why the mass of an object is constant but its weight changes depending on its location.

Give reason why a satellite does not fall down to the Earth despite being in free fall.

Give reason why an athlete must apply a force to start running but does not need to apply a force to maintain uniform motion.

Give reason why a ball thrown in the air reaches a maximum height before falling back to the ground.

Give reason why the force of attraction between two objects increases when their masses increase.

Give reason why it is difficult to stop a moving truck than a moving bicycle.

Give reason why a train cannot instantly change its direction of motion.

Give reason why the friction between two surfaces increases when the roughness of the surfaces increases.

Give reason why air resistance is negligible for a stone falling in a vacuum.

Give reason why wearing seatbelts is important while driving a car.

Give reason why a projectile follows a parabolic path when launched at an angle.

Give reason why inertia is the reason behind a passenger jerking forward when a moving bus suddenly stops.

Give reason why objects fall with the same acceleration due to gravity in a vacuum regardless of their mass.

Give reason why a body moving with uniform velocity has zero acceleration.

Give reason why the work done on an object is zero when it moves perpendicular to the force applied.

Give reason why a satellite in orbit has both kinetic and potential energy.

Give reason why the air resistance acting on an object increases as its velocity increases.

Give reason why it is harder to push a heavy box on a rough surface than on a smooth surface.

Give reason why a ball bounces back when dropped on a hard surface, but it does not bounce back as much on a soft surface.

Give reason why a spring compresses more when a greater force is applied.

Give reason why a machine cannot be 100% efficient.

Give reason why it is difficult to change the direction of a moving object with a larger mass.

Give reason why an object will continue moving in space after the forces acting on it are removed.

Difference between

Difference between speed and velocity.

Difference between mass and weight.

Difference between uniform and non-uniform motion.

Difference between displacement and distance.

Difference between acceleration and deceleration.

Difference between elastic and inelastic collisions.

Difference between kinetic energy and potential energy.

Difference between centripetal force and centrifugal force.

Difference between static friction and kinetic friction.

Difference between gravitational force and normal force.

Difference between work and energy.

Difference between scalar and vector quantities.

Difference between uniform circular motion and non-uniform circular motion.

Difference between force and pressure.

Difference between inertial frame and non-inertial frame of reference.

Difference between contact forces and non-contact forces.

Difference between first law of motion and second law of motion.

Difference between potential energy and mechanical energy.

Difference between linear momentum and angular momentum.

Difference between conservative and non-conservative forces.

Difference between work done by a constant force and work done by a variable force.

Difference between periodic and non-periodic motion.

Difference between gravitational potential energy and elastic potential energy.

Difference between centripetal acceleration and tangential acceleration.

Difference between elastic and plastic deformation.

Difference between free fall and projectile motion.

Difference between force and torque.

Difference between speed and velocity in circular motion.

Difference between rolling friction and sliding friction.

Difference between mass and inertia.

Difference between elastic potential energy and gravitational potential energy.

Difference between kinetic energy and mechanical energy.

Difference between angular velocity and linear velocity.

Difference between force and impulse.

Difference between angular acceleration and linear acceleration.

Difference between uniform velocity and uniform acceleration.

Difference between projectile motion and uniform circular motion.

Difference between action and reaction forces in Newton's third law.

Difference between impulse and momentum.

Difference between mass and density.

Difference between speed-time graph and distance-time graph.

Difference between free fall and uniform motion.

Difference between power and energy.

Difference between gravitational potential energy and kinetic energy during free fall.

Difference between the first and second laws of thermodynamics in relation to motion.

Difference between constant velocity and uniform velocity.

Difference between acceleration due to gravity and gravitational acceleration.

Difference between work done in lifting an object and work done in pulling an object.

Difference between uniform acceleration and non-uniform acceleration.

Difference between uniform motion and non-uniform motion.

Difference between speed and instantaneous velocity.

Difference between translational motion and rotational motion.

Difference between free body diagram and force diagram.

Difference between impulse and work.

Difference between potential energy and kinetic energy in a moving pendulum.

Difference between mass in motion and momentum.

Difference between linear momentum and angular momentum in rotational motion.

Difference between kinetic energy in linear motion and kinetic energy in rotational motion.

Difference between elastic collision and perfectly inelastic collision.

Difference between work and power in relation to machines.

Numerical

Force and Acceleration (Newton's Second Law of Motion)

Problem:
A 5 kg object is subjected to a force of 20 N. Find the acceleration produced in the object.

Solution:
Use Newton's Second Law of Motion:

$$F = ma$$

Where:

• $F = 20 \, N$ (Force)
• $m = 5 \, kg$ (Mass)

Rearranging the formula for acceleration:

$$a = \frac{F}{m} = \frac{20}{5} = 4 \, \text{m/s}^2$$

So, the acceleration produced is $4 \, \text{m/s}^2$.

2. Momentum and its Change (Impulse)

Problem:
A 10 kg object moving at a velocity of 5 m/s comes to rest in 2 seconds. Find the force applied to stop the object.

Solution:
Momentum $p = mv$, where $m = 10 \, kg$ and $v = 5 \, m/s$.

Initial momentum:

$$p = 10 \times 5 = 50 \, \text{kg m/s}$$

Final momentum = 0 (as the object comes to rest).

Change in momentum = $0 - 50 = -50 \, \text{kg m/s}$.

Now, impulse $J = F \times t$, where $t = 2 \, s$.

$$F = \frac{J}{t} = \frac{-50}{2} = -25 \, N$$

So, the force applied is $25 \, N$ in the opposite direction.

3. Work Done by a Force

Problem:
A force of 10 N is applied to move an object over a distance of 5 m in the direction of the force. Find the work done.

Solution:
Work done $W = F \times d$, where:

• $F = 10 \, N$
• $d = 5 \, m$

$$W = 10 \times 5 = 50 \, \text{J}$$

So, the work done is $50 \, \text{J}$.

4. Gravitational Force (Weight)

Problem:
Find the weight of a body of mass 20 kg on the surface of the Earth. (Use $g = 9.8 \, \text{m/s}^2$)

Solution:
Weight $W = mg$, where:

• $m = 20 \, kg$
• $g = 9.8 \, \text{m/s}^2$

$$W = 20 \times 9.8 = 196 \, \text{N}$$

So, the weight of the object is $196 \, \text{N}$.

5. Kinetic Energy

Problem:
Calculate the kinetic energy of a 2 kg object moving with a velocity of 10 m/s.

Solution:
Kinetic Energy $KE = \frac{1}{2} mv^2$, where:

• $m = 2 \, kg$
• $v = 10 \, m/s$

$$KE = \frac{1}{2} \times 2 \times 10^2 = 1 \times 100 = 100 \, \text{J}$$

So, the kinetic energy of the object is $100 \, \text{J}$.

6. Potential Energy

Problem:
Find the potential energy of a 10 kg object placed at a height of 5 m above the ground. (Use $g = 9.8 \, \text{m/s}^2$)

Solution:
Potential Energy $PE = mgh$, where:

• $m = 10 \, kg$
• $g = 9.8 \, \text{m/s}^2$
• $h = 5 \, m$

$$PE = 10 \times 9.8 \times 5 = 490 \, \text{J}$$

So, the potential energy is $490 \, \text{J}$.

7. Speed and Velocity

Problem:
A car travels 100 m in 20 seconds. Find its average speed.

Solution:
Speed $v = \frac{d}{t}$, where:

• $d = 100 \, m$
• $t = 20 \, s$

$$v = \frac{100}{20} = 5 \, \text{m/s}$$

So, the average speed of the car is $5 \, \text{m/s}$.

8. Action and Reaction (Newton's Third Law of Motion)

Problem:
A 1000 kg car is moving with a velocity of 20 m/s. Calculate the momentum of the car.

Solution:
Momentum $p = mv$, where:

• $m = 1000 \, kg$
• $v = 20 \, m/s$

$$p = 1000 \times 20 = 20000 \, \text{kg m/s}$$

So, the momentum of the car is $20000 \, \text{kg m/s}$.

---

9. Force of Friction

Problem:
A box of mass 15 kg is pushed with a force of 50 N on a horizontal surface. If the frictional force acting on the box is 20 N, what is the net force acting on the box?

Solution:
Net force $F_{\text{net}} = F_{\text{applied}} - F_{\text{friction}}$, where:

• $F_{\text{applied}} = 50 \, N$
• $F_{\text{friction}} = 20 \, N$

$$F_{\text{net}} = 50 - 20 = 30 \, N$$

So, the net force acting on the box is $30 \, N$.

---

10. Work-Energy Theorem

Problem:
A 50 kg person climbs a staircase of height 10 m. Calculate the work done by the person against gravity.

Solution:
Work done $W = mgh$, where:

• $m = 50 \, kg$
• $g = 9.8 \, \text{m/s}^2$
• $h = 10 \, m$

$$W = 50 \times 9.8 \times 10 = 4900 \, \text{J}$$

So, the work done is $4900 \, \text{J}$.

---

11. Acceleration due to Gravity (Free Fall)

Problem:
A ball is dropped from a height of 80 meters. Calculate the time it takes for the ball to hit the ground. (Assume $g = 9.8 \, \text{m/s}^2$ and neglect air resistance).

Solution:
Use the equation for free fall:

$$h = \frac{1}{2} g t^2$$

Where:

• $h = 80 \, m$
• $g = 9.8 \, \text{m/s}^2$

Rearranging for $t$:

$$t = \sqrt{\frac{2h}{g}} = \sqrt{\frac{2 \times 80}{9.8}} = \sqrt{\frac{160}{9.8}} \approx \sqrt{16.33} \approx 4.04 \, \text{s}$$

So, the time taken to hit the ground is approximately $4.04 \, \text{seconds}$.

---

12. Circular Motion (Centripetal Force)

Problem:
A car of mass 800 kg is moving in a circular path of radius 50 m with a speed of 20 m/s. Calculate the centripetal force acting on the car.

Solution:
Centripetal force $F_c = \frac{mv^2}{r}$, where:

• $m = 800 \, kg$
• $v = 20 \, m/s$
• $r = 50 \, m$

$$F_c = \frac{800 \times 20^2}{50} = \frac{800 \times 400}{50} = \frac{320000}{50} = 6400 \, N$$

So, the centripetal force acting on the car is $6400 \, N$.

---

13. Power

Problem:
A machine does 500 J of work in 10 seconds. Calculate the power of the machine.

Solution:
Power $P = \frac{W}{t}$, where:

• $W = 500 \, J$
• $t = 10 \, s$

$$P = \frac{500}{10} = 50 \, \text{W}$$

So, the power of the machine is $50 \, \text{W}$.

---

14. Relative Velocity

Problem:
A train is moving at 60 km/h. A passenger is moving in the same direction inside the train at a speed of 10 km/h. What is the speed of the passenger relative to an observer outside the train?

Solution:
Relative velocity $v_{\text{relative}} = v_{\text{train}} - v_{\text{passenger}}$, where:

• $v_{\text{train}} = 60 \, \text{km/h}$
• $v_{\text{passenger}} = 10 \, \text{km/h}$

$$v_{\text{relative}} = 60 - 10 = 50 \, \text{km/h}$$

So, the speed of the passenger relative to an observer outside the train is $50 \, \text{km/h}$.

---

15. Elastic Collision

Problem:
Two identical balls, one stationary and one moving with a velocity of 10 m/s, collide elastically. If the mass of both balls is 2 kg, calculate the velocity of each ball after collision.

Solution:
In an elastic collision, the velocities of the two balls will swap if they have equal masses. Since the balls are identical in mass, the velocities after collision will be:

• The first ball will have a velocity of 0 m/s.
• The second ball will have a velocity of 10 m/s.

Thus, after the elastic collision, the first ball is stationary, and the second ball moves with the original speed of the first ball.

Best Of Luck