Newton’s First Law — Inertia
1. A passenger in a moving bus falls forward when the bus suddenly stops. This is due to:
(A) Inertia of rest
(B) Inertia of motion
(C) Centripetal force
(D) Gravitational force
Answer: (B) Inertia of motion
Explanation: The passenger’s body tends to continue moving forward even after the bus stops.
2. When a stationary bus suddenly starts moving, passengers tend to fall backward because of:
(A) Inertia of motion
(B) Inertia of rest
(C) Centrifugal force
(D) Friction
Answer: (B) Inertia of rest
Explanation: The body tends to remain at rest while the bus moves forward.
3. Dust is removed from a carpet by beating it with a stick because of:
(A) Friction
(B) Inertia
(C) Gravity
(D) Momentum
Answer: (B) Inertia
Explanation: The carpet moves suddenly, but the dust tends to remain at rest and separates from it.
4. When a coin placed on a card is suddenly flicked, the coin falls into the glass below. This demonstrates:
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law
(D) Law of gravitation
Answer: (A) Newton’s first law
Explanation: The coin tends to remain at rest due to inertia when the card is removed quickly.
5. Seat belts in cars are primarily designed to protect passengers from:
(A) Gravity
(B) Inertia
(C) Centripetal force
(D) Friction
Answer: (B) Inertia
Explanation: During sudden braking or collision, the body tends to continue moving forward. The seat belt restrains it.
6. When a bus takes a sharp turn, passengers tend to lean outward. This is due to:
(A) Inertia
(B) Gravity
(C) Friction
(D) Magnetic force
Answer: (A) Inertia
7. A person jumping from a moving bus is likely to fall forward because:
(A) The ground pushes the person forward
(B) The person’s body retains its forward motion
(C) Gravity acts horizontally
(D) Friction increases the forward velocity
Answer: (B) The person’s body retains its forward motion
8. A magician quickly pulls a tablecloth from under objects placed on it without disturbing them significantly. This is based mainly on:
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law
(D) Conservation of energy
Answer: (A) Newton’s first law
Newton’s Second Law
9. According to Newton’s second law, the acceleration of an object is directly proportional to:
(A) Its mass
(B) The net force acting on it
(C) Its volume
(D) Its density
Answer: (B) The net force acting on it
10. If the same force is applied to two objects of different masses, the object with smaller mass will have:
(A) Smaller acceleration
(B) Greater acceleration
(C) Zero acceleration
(D) The same acceleration
Answer: (B) Greater acceleration
11. A football accelerates more when kicked harder because:
(A) Its mass increases
(B) Greater force produces greater acceleration
(C) Gravity becomes stronger
(D) Its momentum becomes zero
Answer: (B) Greater force produces greater acceleration
12. Why is it easier to push an empty shopping cart than a fully loaded one with the same force?
(A) The empty cart has greater friction
(B) The empty cart has less mass and therefore greater acceleration
(C) Gravity does not act on an empty cart
(D) The loaded cart has no inertia
Answer: (B) The empty cart has less mass and therefore greater acceleration
13. A cricket player moves his hands backward while catching a fast ball mainly to:
(A) Increase the force of impact
(B) Decrease the time of impact
(C) Increase the time of impact and reduce the force
(D) Increase the speed of the ball
Answer: (C) Increase the time of impact and reduce the force
14. Why are airbags used in cars?
(A) To increase the speed of passengers
(B) To increase the time over which passengers are brought to rest
(C) To increase the momentum of passengers
(D) To decrease the mass of passengers
Answer: (B) To increase the time over which passengers are brought to rest
15. A goalkeeper pulls his hands backward while stopping a fast football. The purpose is to:
(A) Increase momentum
(B) Increase stopping time and reduce impact force
(C) Increase acceleration
(D) Reduce the mass of the ball
Answer: (B) Increase stopping time and reduce impact force
16. A person falls on a soft mattress rather than a concrete floor with less injury because the mattress:
(A) Increases the stopping time
(B) Increases the person’s mass
(C) Increases gravitational force
(D) Eliminates inertia
Answer: (A) Increases the stopping time
Newton’s Third Law
17. A person is able to walk because:
(A) The person pushes the ground forward
(B) The ground pushes the person forward
(C) Gravity pushes the person forward
(D) Air pushes the person forward
Answer: (B) The ground pushes the person forward
Explanation: The foot pushes the ground backward; the ground exerts an equal and opposite force on the foot.
18. Swimming is an application of:
(A) Newton’s first law
(B) Newton’s second law only
(C) Newton’s third law
(D) Law of gravitation
Answer: (C) Newton’s third law
19. A swimmer moves forward by:
(A) Pushing water backward
(B) Pushing water forward
(C) Pulling water upward
(D) Reducing friction to zero
Answer: (A) Pushing water backward
20. A boat moves forward when a person rows it because:
(A) The oar pushes water backward
(B) Water disappears behind the boat
(C) Gravity pulls the boat forward
(D) The oar reduces the mass of the boat
Answer: (A) The oar pushes water backward
21. The recoil of a gun when a bullet is fired is an application of:
(A) Newton’s first law only
(B) Newton’s second law only
(C) Newton’s third law and conservation of momentum
(D) Law of flotation
Answer: (C) Newton’s third law and conservation of momentum
22. A rocket moves upward because:
(A) It pushes the Earth downward
(B) It expels gases downward
(C) Gravity pushes it upward
(D) Atmospheric pressure pulls it upward
Answer: (B) It expels gases downward
23. Which of the following is the best example of Newton’s third law?
(A) A passenger falling forward when a bus stops
(B) A stone falling from a height
(C) A swimmer pushing water backward and moving forward
(D) A ball remaining at rest
Answer: (C) A swimmer pushing water backward and moving forward
24. Birds are able to fly mainly because their wings:
(A) Push air downward, producing an upward reaction
(B) Eliminate gravity
(C) Increase their mass
(D) Push air upward only
Answer: (A) Push air downward, producing an upward reaction
Mixed Application-Based Questions
25. A person wearing roller skates pushes a wall and moves backward. This illustrates:
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law
(D) Archimedes’ principle
Answer: (C) Newton’s third law
26. When a horse pulls a cart, the horse moves forward because:
(A) The horse pulls the cart forward only
(B) The cart pulls the horse forward
(C) The horse pushes the ground backward and the ground pushes the horse forward
(D) Gravity pulls the horse forward
Answer: (C) The horse pushes the ground backward and the ground pushes the horse forward
27. Why does a person lean forward when starting to run?
(A) Due to inertia
(B) Due to buoyancy
(C) Due to magnetic force
(D) Due to radiation
Answer: (A) Due to inertia
28. A fireman experiences a backward push when water comes out of a high-pressure hose. This is mainly an application of:
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law
(D) Newton’s law of gravitation
Answer: (C) Newton’s third law
29. When a batsman hits a cricket ball with greater force, the ball travels faster. This illustrates:
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law only
(D) Law of conservation of mass
Answer: (B) Newton’s second law
30. Which pair is incorrectly matched?
(A) Seat belt — Inertia
(B) Rocket propulsion — Newton’s third law
(C) Walking — Newton’s third law
(D) Dusting carpet — Newton’s second law
Answer: (D) Dusting carpet — Newton’s second law
Explanation: Dusting a carpet is a classic application of Newton’s first law (inertia).
Quick Revision: Newton’s Laws in Daily Life
| Everyday application | Principle |
| Bus suddenly stops | Inertia of motion |
| Bus suddenly starts | Inertia of rest |
| Dusting carpet | Inertia |
| Seat belt | Inertia |
| Tablecloth trick | Inertia |
| Sharp turn in vehicle | Inertia |
| Kicking a football | Newton’s 2nd law |
| Pushing shopping cart | Newton’s 2nd law |
| Catching a cricket ball | Newton’s 2nd law |
| Airbags | Newton’s 2nd law |
| Walking | Newton’s 3rd law |
| Swimming | Newton’s 3rd law |
| Rowing a boat | Newton’s 3rd law |
| Rocket propulsion | Newton’s 3rd law |
| Gun recoil | Newton’s 3rd law + momentum |
| Fire hose recoil | Newton’s 3rd law |
| Bird flight | Newton’s 3rd law |
| Horse pulling cart | Newton’s 3rd law |