Force and Laws of Motion Class 9 MCQs help students understand how force affects the motion of objects in everyday life. From pushing a trolley to kicking a football, force plays an important role in changing the speed, direction, or state of motion of an object. This chapter explains important Physics concepts like inertia, momentum, Newton’s laws of motion, and the relationship between force and acceleration.
Students usually find this chapter interesting because many concepts are connected with real-life examples. At the same time, application-based and numerical questions often create confusion during exams. Questions based on balanced forces, action-reaction pairs, and momentum calculations require proper conceptual understanding instead of direct memorisation. That is why regular practice of Force and Laws of Motion Class 9 MCQs becomes important for improving accuracy and problem-solving skills.
These MCQs are prepared according to the latest CBSE Board and NCERT syllabus. The questions help students strengthen Physics concepts, improve numerical understanding, and prepare more confidently for school tests, periodic assessments, and final examinations.
Important Concepts Covered in Force and Laws of Motion MCQs
These Force and Laws of Motion Class 9 MCQs cover all major concepts from Chapter 8 of Class 9 Science.
- Force
- Balanced and unbalanced forces
- Newton’s first law of motion
- Newton’s second law of motion
- Newton’s third law of motion
- Inertia
- Momentum
- Law of conservation of momentum
- Force and acceleration relationship
- Action and reaction forces
- Numerical problems based on F = ma
- Real-life applications of Newton’s laws
Some questions are concept-based while others require numerical calculations and logical reasoning.
Real-Life Examples Based on Newton’s Laws of Motion
Many concepts from this chapter can be understood more easily through daily-life situations.
- Seat belts help reduce the effect of inertia during sudden braking.
- A football moves only when force is applied to it.
- While walking, we push the ground backward and the ground pushes us forward.
- Recoil of a gun is an example of Newton’s third law of motion.
- Catching a fast cricket ball with moving hands helps reduce force due to increased time of impact.
Questions based on practical applications of Newton’s laws are commonly asked in school examinations.
Class 9 Science Chapter 8 MCQs with Answers
Q. A student pushes a heavy box across a rough floor. Initially, the box does not move, but with increased effort, it starts sliding. Which statement best explains this phenomenon?
A) The applied force was less than the kinetic friction initially, then exceeded it.
B) The applied force was less than the static friction initially, then exceeded it.
C) The box has a large mass, requiring a significant force to overcome its inertia.
D) The normal force acting on the box decreased, making it easier to move.
Answer: B
Explanation: Static friction prevents motion initially. Once the applied force exceeds static friction, the box starts moving.
Q. Consider a book resting on a table. Which statement accurately describes the forces acting on the book?
A) The gravitational force is greater than the normal force.
B) The forces are unbalanced.
C) The gravitational force is balanced by the normal force.
D) No forces act on the book.
Answer: C
Explanation:
The downward gravitational force and upward normal force are equal, so the book remains at rest.
Q. A passenger standing in a moving bus falls forward when the bus suddenly applies brakes. This is explained by:
A) Newton’s Second Law
B) Newton’s Third Law
C) Conservation of Momentum
D) Inertia of Motion
Answer: D
Explanation: The body tends to remain in motion due to inertia, so the passenger falls forward.
Q. Which scenario demonstrates a change in momentum?
A) A car moving at constant speed in a straight line
B) A satellite orbiting Earth at constant speed
C) A block resting on a frictionless surface
D) A stationary object on the ground
Answer: B
Explanation:
Momentum changes when velocity direction changes. A satellite continuously changes direction while orbiting.
Q. A hockey player hits a puck on a frictionless ice surface. After being hit, the puck will:
A) Slow down due to air resistance
B) Continue moving at constant velocity indefinitely
C) Curve due to Earth’s rotation
D) Accelerate continuously
Answer: B
Explanation: Without friction, no external force acts to stop the puck.
Q. A force of 10 N acts on a 2 kg object. What is the acceleration produced?
A) 0.2 m/s²
B) 5 m/s²
C) 20 m/s²
D) 10 m/s²
Answer: B
Explanation: Using ( F = ma ), acceleration = ( 10/2 = 5 , m/s^2 ).
Q. When a rocket takes off, exhaust gases are expelled downward at high speed. Which law explains the upward thrust?
A) Newton’s First Law
B) Newton’s Second Law
C) Newton’s Third Law
D) Law of Conservation of Momentum
Answer: C
Explanation: The gases pushed downward create an equal and opposite upward reaction force.
Q. A 5 kg object moving at 10 m/s collides with a 10 kg object at rest. After collision, the 5 kg object moves backward at 2 m/s. Find the velocity of the 10 kg object.
A) 4 m/s
B) 6 m/s
C) 8 m/s
D) 3 m/s
Answer: B
Explanation:
Using conservation of momentum:
( 5(10) = 5(-2) + 10v )
( 50 = -10 + 10v )
( v = 6 , m/s )
Q. Why is it more difficult to stop a heavy truck than a small car moving at the same speed?
A) Higher acceleration
B) Greater momentum
C) More air resistance
D) Less friction
Answer: B
Explanation: Momentum depends on mass and velocity. Greater mass means greater momentum.
Q. A person jumps out of a boat onto the shore. Why does the boat move backward?
A) Person’s weight pushes the boat
B) Less friction on water
C) Action-reaction pair
D) Person pulls the boat backward
Answer: C
Explanation: According to Newton’s Third Law, the boat experiences an equal and opposite reaction.
Q. An object is moving with constant velocity. Which statement is true?
A) No forces act on it
B) Net force is zero
C) Forces are unbalanced
D) It is accelerating
Answer: B
Explanation: Constant velocity means zero acceleration, so net force must be zero.
Q. A car takes a sharp turn at high speed. Passengers are thrown sideways due to:
A) Centripetal force
B) Inertia of direction
C) Newton’s Third Law
D) Centrifugal force
Answer: B
Explanation: Passengers tend to continue in their original direction due to inertia.
Q. If velocity is doubled, what happens to momentum?
A) Remains same
B) Halved
C) Doubled
D) Quadrupled
Answer: C
Explanation: Momentum ( p = mv ). Doubling velocity doubles momentum.
Q. Why are seat belts crucial in vehicles?
A) Increase impact force
B) Reduce collision time
C) Increase collision time and reduce force
D) Prevent acceleration
Answer: C
Explanation:
Increasing impact time reduces force according to impulse principles.
Q. Which example demonstrates inertia of rest?
A) Cyclist moving after pedaling stops
B) Dust particles coming off carpet when beaten
C) Coin moving on carrom board
D) Pendulum swinging
Answer: B
Explanation: Dust particles tend to remain at rest while the carpet moves suddenly.
Q. What is the SI unit of momentum?
A) Newton
B) Joule
C) kg m/s
D) kg m/s²
Answer: C
Explanation: Momentum = mass × velocity, so SI unit is kg m/s.
Q. Newton’s Second Law states:
A) Every action has equal reaction
B) Rate of change of momentum is proportional to force
C) Object stays at rest unless acted upon
D) Force proportional to square of acceleration
Answer: B
Explanation: Newton’s Second Law directly relates force to rate of change of momentum.
Q. Which is NOT an action-reaction pair?
A) Earth pulls apple and apple pulls Earth
B) Wall pushes ball and ball pushes wall
C) Tires push road and road pushes tires
D) Gravity pulls book and table pushes book
Answer: D
Explanation: These two forces act on the same object, so they are not an action-reaction pair.
Q. A cricketer pulls his hands back while catching a ball to:
A) Increase momentum
B) Decrease impact time
C) Increase impact time and reduce force
D) Reduce change in momentum
Answer: C
Explanation: Increasing stopping time reduces the force experienced.
Q. How is inertia related to mass?
A) Inversely proportional
B) Directly proportional
C) Independent
D) Proportional to square of mass
Answer: B
Explanation: Greater mass means greater resistance to change in motion.
Q. Which expression gives the magnitude of force?
A) (F = m(v-u))
B) (F = \frac{m(v-u)}{t})
C) (F = \frac{(v-u)}{mt})
D) (F = mvt)
Answer: B
Explanation: Force = rate of change of momentum.
Q. When a bullet is fired from a gun, the gun recoils because of:
A) Newton’s First Law
B) Newton’s Second Law
C) Newton’s Third Law
D) Inertia of Rest
Answer: C
Explanation: The bullet moves forward while the gun experiences an equal backward reaction.
Q. Impulse is defined as:
A) Rate of change of momentum
B) Force × distance
C) Force × time
D) Change in kinetic energy
Answer: C
Explanation: Impulse equals force multiplied by time duration.
Q. A ball rolling on a rough surface stops because of:
A) Gravity
B) Normal force
C) Friction
D) Air resistance
Answer: C
Explanation: Friction opposes motion and eventually stops the ball.
Q. Which statement about Newton’s Laws is incorrect?
A) First Law defines inertia
B) Second Law measures force quantitatively
C) Third Law forces act on same object
D) Laws apply in inertial frames
Answer: C
Explanation: Action and reaction forces act on different objects.
Q. Momentum is a vector quantity because it has:
A) Only magnitude
B) Only direction
C) Magnitude and direction
D) Neither
Answer: C
Explanation: Momentum depends on velocity, which has direction.
Q. Which is an example of a non-contact force?
A) Frictional force
B) Normal force
C) Muscular force
D) Gravitational force
Answer: D
Explanation: Gravity acts without physical contact.
Q. If net force is doubled while mass remains constant, acceleration becomes:
A) Same
B) Half
C) Double
D) Quadruple
Answer: C
Explanation: According to ( F = ma ), acceleration is directly proportional to force.
Q. Which best defines a force?
A) Property resisting motion
B) Push or pull changing motion
C) Amount of matter
D) Speed of position change
Answer: B
Explanation: Force is a push or pull that can change an object’s motion.
Q. Is force a scalar or vector quantity?
A) Scalar with magnitude only
B) Vector with magnitude and direction
C) Scalar without direction
D) Vector with direction only
Answer: B
Explanation: Force has both magnitude and direction, so it is a vector quantity.
Instructions for Students Before Solving the MCQs
- Revise Newton’s laws carefully before attempting conceptual questions.
- Read numerical values properly during momentum and force calculations.
- Focus on understanding action-reaction force pairs correctly.
- Do not confuse balanced force with unbalanced force.
- Observe the direction of force carefully in application-based questions.
- Practice conceptual examples regularly along with formulas.
- Re-attempt incorrect questions after revision for better understanding.
Sometimes students remember the law correctly but still choose the wrong option because they misunderstand the situation given in the question.
Common Confusions in Force and Laws of Motion MCQs
Many students lose marks because of small conceptual confusion in Physics objective questions. Some common mistakes are listed below.
- Confusing balanced force with unbalanced force
- Incorrect understanding of inertia
- Mixing momentum with force
- Wrong identification of action and reaction forces
- Sign mistakes in numerical calculations
- Incorrect use of F = ma formula
- Selecting answers without understanding the direction of force properly
Most mistakes happen when students memorise the laws without understanding their practical application.
Why Practice Force and Laws of Motion Class 9 MCQs?
Practicing Force and Laws of Motion Class 9 MCQs helps students improve conceptual clarity and numerical problem-solving skills. Since this chapter contains both theoretical and application-based concepts, regular MCQ practice becomes important for proper exam preparation.
- These objective questions help students:
- Understand Newton’s laws more clearly
- Improve momentum and force calculations
- Strengthen application-based reasoning
- Prepare for school exams and tests
- Improve confidence in Physics numericals
Regular practice also helps students identify weak areas and reduce conceptual confusion during revision.
Conclusion
Practicing Force and Laws of Motion Class 9 MCQs regularly helps students strengthen their understanding of force, inertia, momentum, and Newton’s laws of motion. These objective questions improve conceptual clarity, numerical accuracy, and application-based reasoning, helping students prepare more effectively for Class 9 Science examinations.