Class 9 • Physics • Chapter 8
FORCE AND LAWS OF MOTION
True & False Quiz
Inertia. Force. Momentum.
✓True
✗False
24
Questions
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Ch.8
Chapter
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IX
Class
Why True & False for FORCE AND LAWS OF MOTION?
How this format sharpens your conceptual clarity
🔵 Newton's Laws of Motion are the cornerstone of classical mechanics — they explain everything from a ball rolling to a rocket launching.
✅ T/F tests all three Newton's laws, inertia, momentum, impulse, and conservation of momentum.
🎯 Newton's Third Law states action and reaction are equal and opposite — but they act on DIFFERENT objects, so they do NOT cancel each other out.
📋
Read each statement carefully. Click True or False — instant feedback with explanation appears. Submit anytime; unattempted questions are marked Skipped.
Q 1
Force is required to change the state of motion of a body.
Q 2
A body at rest will always remain at rest even if an external force is applied.
Q 3
Inertia is the tendency of a body to oppose changes in its state of motion.
Q 4
Newton’s First Law of Motion is also called the Law of Inertia.
Q 5
If no force acts on a body, it will eventually come to rest.
Q 6
Force is directly proportional to the rate of change of momentum.
Q 7
Impulse is equal to the change in momentum of a body.
Q 8
The SI unit of force is Joule.
Q 9
1 Newton force is that which produces an acceleration of 1 m/s² in a body of mass 1 kg.
Q 10
Momentum of a body depends only on its velocity.
Q 11
Every action has an equal and opposite reaction.
Q 12
Action and reaction forces act on the same body.
Q 13
When a gun is fired, the backward recoil is an example of Newton’s Third Law.
Q 14
Seat belts are used in cars to reduce the effect of inertia during sudden braking.
Q 15
A ball moving on a frictionless surface will stop after some time on its own.
Q 16
Walking is possible because of Newton’s Third Law of Motion.
Q 17
The momentum of an isolated system is always conserved.
Q 18
If two bodies collide, the total momentum before and after collision is the same (in absence of external force).
Q 19
In a collision, individual momentum of each body always remains constant.
Q 20
Acceleration produced in a body is inversely proportional to its mass.
Q 21
Force has both magnitude and direction.
Q 22
Heavier objects have less inertia than lighter ones.
Q 23
Newton’s Laws of Motion are applicable only to moving objects, not to objects at rest.
Q 24
Friction always opposes the relative motion of surfaces in contact.
Key Takeaways — FORCE AND LAWS OF MOTION
Core facts for CBSE Boards & exams
1
First Law (Inertia): an object remains at rest or in uniform motion unless acted upon by an external force.
2
Inertia is proportional to mass — heavier objects have greater inertia.
3
Second Law: F = ma; Force = rate of change of momentum; 1 Newton = 1 kg·m/s².
4
Third Law: every action has an equal and opposite reaction (on different bodies).
5
Momentum (p) = mass × velocity; unit = kg·m/s; vector quantity.
6
Law of Conservation of Momentum: total momentum before = total momentum after (no external force).