Newton’s Third Law of the Motion and Conservation of the Momentum:Class 11CBSE Physics

Newton’s Third Law of the Motion and Conservation of the Momentum: Newton’s third law of motion states that every action has an equal and opposite reaction. Action and reaction act on two different bodies. The biggest application of Newton’s law of the motion is propulsion of the rocket into space, in the rocket there is an exit at the downward or back portion of the fuel tank, and the fuel is forcibly ejected from the exit in such a way that equal reaction occurs against the action of flushed products which are produced as a result of the combustion of the fuel.The reactive force propels the rocket into the atmosphere and settles down the rocket into the space.

Newton’s Third Law of the Motion and Conservation of the Momentum: Class 11CBSE Physics

In Newton’s third law of motion, the action and reaction pair must have the following condition.

(i)Action and reaction in Newton’s third law are always of the same nature.

(ii)Action and reaction in Newton’s third law act on two different bodies.

(iii)Force always exist in pair.

Example: An object kept on a plane, the force exerted by an object to another object(plane) is the normal reaction which is equal to the force exerted by another object(plane) to the previous object is the normal reaction. In this case, gravitational force or weight(mg) which acts on the object in the downward direction, and normal reaction are not the action and reaction pair while both of them are equal because mg and N are not of a similar nature and also act on the same object.

In this case, the object also pulls the earth by the same force mg that makes the action-reaction pair with the weight of the object.

Here, N_PO,N_OP and Mg_EO,Mg_OE are the action and reaction pair in Newton’s thirld law of motion.

Where,

N_PO is the normal reaction from plane to object

N_OP is the noral reaction from object to the plane

Mg_EO is the gravitational force applied by the earth to object

Mg_OE is the gravitational force applied by the object to the earth

Conservation of the momentum:In an isolated system the momentum of the system is always constant or the change in momentum is zero. The net force on the isolated system is 0, we have

F_net =0

F_net =ΔP/ΔT

0 =ΔP/ΔT

ΔP = 0

Therefore P is constant

Let initial momentum of the system is P_I  and and final momentum is P_F

Then

P_I  = P_F

Let there are two marbles of the masses  m₁  and m₂ moving with a velocities u₁ and u₂colloids to each other and after collision their velocities turnes to v₁ and v₂

Then

P_I  =   m₁ u₁ + m₂ u₁

P_F = m₁ v₁ + m₂ v₂

Therefore

m₁ u₁ + m₂ u₁= m₁ v₁ + m₂ v₂

Note: Isolated system means no any external force is applied on the system.

Conservation of the momentum by the third law: Class 11 CBSE Physics

Let two marbles collide to each other, then the force applied by one marble to another marble is F and according to Newton’s third law, second marble will also apply the same force to the first marble.

Let two marbles are A and B and the forces applied by them to each other are F_AB and F_BA

F_AB =- F_BA

Let the acceleration produced by the forces on the marbles are a₁ and a₂

F_AB =m₁a₁=m₁(v₁-u₁)/t

F_BA =m₂a₂=m₂(v₂-u₂)/t

m₁(v₁-u₁)/t =-m₂(v₂-u₂)/t

m₁(v₁-u₁) =-m₂(v₂-u₂)

m₁v₁-m₁u₁ = -m₂v₂+m₂u₂

m₁u₁ +m₂u₂=m₁v₁ + m₂v₂

Class 11 Physics and Chemistry Notes

Static and Kinetic Friction :Class 11 CBSE Physics Chapter 5

Forces and Newton’s First Laws of motion:Class 11 Physics Chapter 5 CBSE

You can also study class 11 Physics and Chemistry Notes

Circular Motion: Angular velocity and angular displacement

Projectile Motion Class 11 CBSE Physics Chapter 4 Motion in a Plane

Addition of Vectors: CBSE Class 11 Physics Chapter 4 -Motion in a Plane

Don’t forget to write a comment, subscribe us for the posts related to your study

Lattice Energy Class 11 CBSE Chemistry Chapter 4

Electronic Configuration of s,p and d orbitals

Atomic Radius Class 11 Chemistry Chapter 3 Periodicity in Properties

Why does a Rainbow look like a Bow?

NCERT Solutions of Science and Maths for Class 9,10,11 and 12

NCERT Solutions for class 9 maths

Chapter 1- Number System	Chapter 9-Areas of parallelogram and triangles
Chapter 2-Polynomial	Chapter 10-Circles
Chapter 3- Coordinate Geometry	Chapter 11-Construction
Chapter 4- Linear equations in two variables	Chapter 12-Heron’s Formula
Chapter 5- Introduction to Euclid’s Geometry	Chapter 13-Surface Areas and Volumes
Chapter 6-Lines and Angles	Chapter 14-Statistics
Chapter 7-Triangles	Chapter 15-Probability
Chapter 8- Quadrilateral

NCERT Solutions for class 9 science 

Chapter 1-Matter in our surroundings	Chapter 9- Force and laws of motion
Chapter 2-Is matter around us pure?	Chapter 10- Gravitation
Chapter3- Atoms and Molecules	Chapter 11- Work and Energy
Chapter 4-Structure of the Atom	Chapter 12- Sound
Chapter 5-Fundamental unit of life	Chapter 13-Why do we fall ill ?
Chapter 6- Tissues	Chapter 14- Natural Resources
Chapter 7- Diversity in living organism	Chapter 15-Improvement in food resources
Chapter 8- Motion	Last years question papers & sample papers

NCERT Solutions for class 10 maths

Chapter 1-Real number	Chapter 9-Some application of Trigonometry
Chapter 2-Polynomial	Chapter 10-Circles
Chapter 3-Linear equations	Chapter 11- Construction
Chapter 4- Quadratic equations	Chapter 12-Area related to circle
Chapter 5-Arithmetic Progression	Chapter 13-Surface areas and Volume
Chapter 6-Triangle	Chapter 14-Statistics
Chapter 7- Co-ordinate geometry	Chapter 15-Probability
Chapter 8-Trigonometry

Class 10 Maths Question Paper CBSE Half Yearly Exam 2022 With Solutions

CBSE Class 10-Question paper of maths 2021 with solutions

CBSE Class 10-Half yearly question paper of maths 2020 with solutions

CBSE Class 10 -Question paper of maths 2020 with solutions

CBSE Class 10-Question paper of maths 2019 with solutions

NCERT Solutions for Class 10 Science

Chapter 1- Chemical reactions and equations	Chapter 9- Heredity and Evolution
Chapter 2- Acid, Base and Salt	Chapter 10- Light reflection and refraction
Chapter 3- Metals and Non-Metals	Chapter 11- Human eye and colorful world
Chapter 4- Carbon and its Compounds	Chapter 12- Electricity
Chapter 5-Periodic classification of elements	Chapter 13-Magnetic effect of electric current
Chapter 6- Life Process	Chapter 14-Sources of Energy
Chapter 7-Control and Coordination	Chapter 15-Environment
Chapter 8- How do organisms reproduce?	Chapter 16-Management of Natural Resources

NCERT Solutions for class 11 maths

Chapter 1-Sets	Chapter 9-Sequences and Series
Chapter 2- Relations and functions	Chapter 10- Straight Lines
Chapter 3- Trigonometry	Chapter 11-Conic Sections
Chapter 4-Principle of mathematical induction	Chapter 12-Introduction to three Dimensional Geometry
Chapter 5-Complex numbers	Chapter 13- Limits and Derivatives
Chapter 6- Linear Inequalities	Chapter 14-Mathematical Reasoning
Chapter 7- Permutations and Combinations	Chapter 15- Statistics
Chapter 8- Binomial Theorem	Chapter 16- Probability

CBSE Class 11-Question paper of maths 2015

CBSE Class 11 – Second unit test of maths 2021 with solutions

NCERT Solutions for Class 11 Physics

Chapter 1- Physical World

chapter 3-Motion in a Straight Line

NCERT Solutions for Class 11 Chemistry

Chapter 1-Some basic concepts of chemistry

Chapter 2- Structure of Atom

NCERT Solutions for Class 11 Biology

Chapter 1 -Living World

NCERT solutions for class 12 maths

Chapter 1-Relations and Functions	Chapter 9-Differential Equations
Chapter 2-Inverse Trigonometric Functions	Chapter 10-Vector Algebra
Chapter 3-Matrices	Chapter 11 – Three Dimensional Geometry
Chapter 4-Determinants	Chapter 12-Linear Programming
Chapter 5- Continuity and Differentiability	Chapter 13-Probability
Chapter 6- Application of Derivation	CBSE Class 12- Question paper of maths 2021 with solutions
Chapter 7- Integrals
Chapter 8-Application of Integrals

Class 12 Solutions of Maths Latest Sample Paper Published by CBSE for 2021-22 Term 2

Class 12 Maths Important Questions-Application of Integrals

Class 12 Maths Important questions on Chapter 7 Integral with Solutions for term 2 CBSE Board 2021-22

Solutions of Class 12 Maths Question Paper of Preboard -2 Exam Term-2 CBSE Board 2021-22

Solutions of class 12  maths question paper 2021 preboard exam CBSE Solution