Class 11 Physics Important Chapter 5 Law of Motion

Class 11 Physics Important Chapter 5 Law of Motion Solutions English Medium As Per AHSEC New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters NCERT Class 11 Physics Important Solutions and select need one. AHSEC Class 11 Physics Additional Notes English Medium Download PDF. HS 1st Year Physics Important Solutions in English.

Class 11 Physics Important Chapter 5 Law of Motion

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. NCERT Class 11 Physics Additional Question Answer are part of All Subject Solutions. Here we have given HS 1st Year Physics Important Notes in English for All Chapters, You can practice these here.

Law of Motion

Chapter: 5

IMPORTANT QUESTION AND ANSWER

Answer the Following Questions:

1. What is Newton’s First Law of Motion?

Ans: (i) A body remains in its state of rest or uniform motion unless acted upon by an external force.

(ii) In simple terms, this law describes inertia—the resistance of a body to change its state of motion.

2. What is inertia?

Ans: (i) The tendency of a body to resist a change in its state of motion or rest.

(ii) It is why you feel pushed back in your seat when a car suddenly accelerates.

3. Define momentum.

Ans: (i) Momentum is the product of an object’s mass and its velocity.

(ii) Formula: Momentum (p) = Mass (m) × Velocity (v)

4. State Newton’s Second Law of Motion.

Ans: (i) The force acting on an object is directly proportional to the rate of change of its momentum.

(ii) Formula: F = dp/dt

In simple words, the force on an object equals its mass multiplied by the acceleration.

5. State Newton’s Third Law of Motion.

Ans: (i) For every action, there is an equal and opposite reaction.

(ii) This law explains why you push down on a skateboard to make yourself move up.

6. What is impulse?

Ans: (i) Impulse is the change in momentum resulting from a force applied over a time period.

(ii) Formula: Impulse = Force × Time = Change in Momentum

7. What is the law of conservation of momentum?

Ans: (i) In an isolated system, the total momentum before and after an event remains constant, provided no external force acts on it.

8. Define static friction.

Ans: (i) The force that resists the initiation of motion between two surfaces in contact.

(ii) Example: Pushing a heavy object to start moving it.

9. Define kinetic friction.

Ans: (i) The force that opposes the relative motion of two surfaces already in motion.

(ii) Example: Sliding a box across the floor.

10. What is centripetal force?

Ans: (i) The force required to keep an object moving in a circular path.

(ii) It acts towards the center of the circle.

Formula: Fc = mv²/R

Tips for Understanding Easily

Newton’s First Law = Inertia:

Objects at rest or uniform motion will stay that way unless acted upon by an external force.

2nd Law Formula:

F = ma (Force is simply mass times acceleration.)

Momentum is Key:

For impulse and conservation problems, use the formula p = mv.

Always Draw Free-Body Diagrams:

This helps simplify and visualize forces acting on objects.

In Circular Motion:

Remember that centripetal force is Fc = mv²/R.

Equilibrium:

For a body in equilibrium, the vector sum of all forces is zero.