Class 11 Physics - HARYANA
Laws of Motion
The chapter 'Laws of Motion' in Class 11 Physics builds upon the concept of force and kinematics to explain why objects move the way they do. Students will study Newton's three fundamental laws of motion, the law of conservation of linear momentum, and the mechanics of friction including static, kinetic, and rolling friction. Special emphasis is given to circular motion, banking of roads, and solving numerical problems using free-body diagrams. For Haryana (BSEH) board exams, this is a high-scoring and conceptually vital unit that frequently features both theoretical derivations and numerical problems.
Start Learning FreeKey Concepts
Newton's First Law of Motion
An object continues to remain at rest or in uniform motion along a straight line unless acted upon by an external force; it defines inertia.
Newton's Second Law of Motion
The rate of change of linear momentum of a body is directly proportional to the applied external force and takes place in the direction in which the force acts (F = ma).
Newton's Third Law of Motion
To every action, there is always an equal and opposite reaction acting on two different bodies.
Law of Conservation of Linear Momentum
The total linear momentum of an isolated system of interacting particles remains conserved if no external force acts on it.
Friction
An opposing force that comes into play when one body moves or tends to move over the surface of another body, categorized into static, limiting, and kinetic friction.
Centripetal Force
The internal or external force required to keep a body moving along a circular path, directed towards the center of the circle.
Important Formulas
Board Exam Info
In the Haryana (BSEH) Class 11 Physics examination, the Laws of Motion chapter typically carries around 6 to 8 marks. Common question types include numerical problems on connected bodies and pulleys, derivations of banking of roads or acceleration on an inclined plane, and conceptual questions on inertia and conservation of momentum.
Frequently Asked Questions
Why do action and reaction forces not cancel each other out?
Action and reaction forces do not cancel each other because they act on two different bodies, not on the same body.
What is the difference between static friction and kinetic friction?
Static friction opposes impending motion when the body is at rest, whereas kinetic friction opposes actual relative motion when the body is sliding over a surface.
Why is it easier to pull a lawn mower than to push it?
When pulling a lawn mower, the vertical component of the pulling force acts upwards, decreasing the apparent weight and normal reaction, which reduces the friction. Pushing increases the normal reaction and friction.
Learn Laws of Motion with Your AI Tutor
10 different ways to study this chapter. Free for 3 chapters per day.
Lecture
Key Points
Interactive
Quiz
Flashcards