# Chapter 5 – Laws of Motion

The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

Centuries ago, Sir Isaac Newton’s revolutionary discovery of the motion of the body and the physical forces acting on the body are till date known as Newton’s Laws. Not only do we utilise these laws for every activity but also they are the basis of many theories of physics. These three laws of motion will help you to understand the behaviour of objects. Whether they are still standing or moving and during any physical force act upon them. In this article, we will describe the meaning of Newton’s laws of motion in brief.

#### Newton's First Law of Motion

Newton’s first law of motion states that ‘an object or a body at rest or uniform motion will continue to be at rest or uniform motion in a straight line unless an external force of action is compelled to change’. By this statement, Newton was stating that objects or things can not start, stop or change their direction from a straight line by themselves. To change its direction, some physical force must require from outside to causing a movement. This first Newton’s law of motion is also known as the law of Inertia. When massive body properties in their state of motion, resist changes are known as Inertia.

Now, in this first law of motion, you must understand what the crucial point is. And here, the crucial point is, if there is no external force resulting from unbalanced forces acting on a thing or an object, and then the thing or object will maintain a constant velocity. And if velocity is zero, the object will remain at rest, and it is known as Inertia of Rest. If any external force is applied, then velocity will change because of the external force, and it is known as Inertia of Motion. An object or body in motion in a certain fixed direction will continue its motion in that direction until and unless some external act forces it to change its direction and it is known as Inertia of Direction.

#### Newton's Second Law of Motion

Newton’s Second Law of Motion states ‘the acceleration of an object depends upon two variables –one is the net force that acts upon the object, and the other is the mass of the object’. An object’s acceleration directly depends upon the external force upon that object and contrarily upon the mass of that object. When the force is increased, acting upon an object, then the acceleration of the object is also increased. And when the mass of an object increases, then the acceleration of the object is decreased.

This Second Law of Motion explains what happens to the massive body when an external force is acted upon it. It states that the force which is acting on a body is equal to the product of its acceleration and mass.

Newton’s Second Law of Motion can be mathematically represented as:-

F=m.a

Here,

‘F’ refers to Force ‘m’ refers to Mass of an Object.

‘a’ refers to the acceleration.

#### Newton's Third Law of Motion

Newton’s 3rd Law of Motion states that ‘every action in nature has an equal and opposite reaction‘. This law of motion is also known as Action-Reaction. When two objects interact, the force that they apply to each other is equal in magnitude and opposite in its direction.

To understand Newton’s Third Law, we can take the help of the following example:

When you row a boat and want to move forward, then you paddle to push the water backwards, and this leads you to move forward. Likewise, when you walk, you shove the surface of the floor using your toes. And the surface of the floor shoves your legs up and helps you to lift your leg.

#### FAQs for Laws of Motion

• What are Newton’s 1st, 2nd and 3rd laws of motion?

Ans: The first law of motion states that unless and until a force acts on an object it will not change its motion.

The second law of motion states that a force applied to an object at rest causes it to accelerate in the force direction.

The third law of motion stated that every action in nature has equal and opposite reactions.

• What is another name for Newton’s third law?

Ans: Newton’s third law is also known as Action-Reaction, as it creates an equal part reaction for the action.

• What is Newton’s 4th Law?

Ans: The Law of Gravitation is known as Newton’s 4th Law.

• How many laws of motion are there?

Ans: There are three laws of motion. These are known as Newton’s Laws of Motion.

Newton’s Laws of Motion are very important for all the students to know ‘foundations of classical mechanism’, which is a fundamental chapter in Physics. Newton’s Laws correlate everything you see in your daily life. By these laws of motion, you will be able to think why objects or things move or still sit, why you never fallout from your house floors or why you are not floating on your bed, etc.

For making your learning process easy and interesting, we are offering you the MSVgo app and official site. It is learning through a video app that you can easily download on your mobile from the play store. This MSVgo app will enable students to learn through our videos anytime and from anywhere. Students from class VI to XII of CBSE and ICSE board can enjoy core syllabus learning from this MSVgo app.

### High School Physics

• Alternating Current
• Atoms
• Communication Systems
• Current Electricity
• Dual nature of Radiation and Matter
• Electric Charges and Fields
• Electricity
• Electromagnetic Induction
• Electromagnetic Waves
• Electrons and Photons
• Electrostatic Potential and Capacitance
• Fluid Pressure
• Force and Acceleration
• Force And Laws Of Motion
• Gravitation
• Internal Energy
• Kinetic Theory
• Law of motion
• Light – Reflection And Refraction
• Magnetic Effects Of Electric Current
• Magnetism and Matter
• Management Of Natural Resources
• Mechanical properties of Fluids
• Mechanical properties of Solids
• Motion
• Motion in a plane
• Motion in a straight line
• Moving Charges and Magnetism
• Nuclear Energy
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• Our Environment
• Paths of Heat
• Physical world
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• Semiconductor Devices
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• Simple Machines
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• Vectors, Scalar Quantities and Elementary Calculus
• Wave Optics
• Waves
• Work, Power and Energy

### High School Chemistry

• Acids, Bases and Salts
• Alcohols, Phenols and Ethers
• Aldehydes, Ketones and Carboxylic Acids
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• Analytical Chemistry
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• Basic concepts of Chemistry
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• Chemical Bonding and Molecular Structures
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• Chemistry in Everyday Life
• Chemistry of p-Block elements
• Chemistry of Transition and Inner Transition
• Classification of Elements
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• Electrochemistry
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• Relative Molecular Mass and Mole
• States of Matter
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• Study of Compounds
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• The d-block and f-block elements
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• The p-Block Elements
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### High School Biology

• Absorption and Movement of Water in Plants
• Anatomy of Flowering Plants
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• Circulation
• Control And Coordination
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• Diversity In Living Organisms
• Ecosystem
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• Excretory Products and their Elimination
• Flowering Plants
• Genes and Chromosomes
• Health and Diseases
• Health and Its Significance
• Heredity And Evolution
• Heredity and Variation
• How Do Organisms Reproduce?
• Human Diseases
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• Hygiene
• Improvement In Food Resources
• Integumentary System- Skin
• Kingdom Fungi
• Kingdom Monera
• Kingdom Protista
• Life Processes
• Locomotion and Movement
• Microbes in Human Welfare
• Mineral Nutrition
• Molecular Basis of Inheritance
• Morphology of Flowering Plants
• Neural Control And Coordination
• Nutrition in Human Beings
• Organism and Population
• Photosynthesis
• Photosynthesis in Higher Plants
• Plant Growth and Development
• Plant Kingdom
• Pollination and Fertilization
• Pollution; Sources and its effects
• Principles of Inheritance and Variation
• Reproduction and Development in Angiosperms
• Reproduction in Organisms
• Reproductive Health
• Respiration in Human Beings
• Respiration in Plants
• Respiratory System
• Sexual Reproduction in Flowering Plants
• Strategies for Enhancement in Food Production
• Structural Organisation in Animals
• Structural Organisation of the Cell
• The Endocrine System
• The Fundamental Unit Of Life
• The Living World
• The Nervous System and Sense Organs
• Tissues
• Transpiration
• Transport in Plants

### High School Math

• Algebra – Arithmatic Progressions
• Algebra – Complex Numbers and Quadratic Equations
• Algebra – Linear Inequalities
• Algebra – Pair of Linear Equations in Two Variables
• Algebra – Polynomials
• Algebra – Principle of Mathematical Induction
• Binomial Theorem
• Calculus – Applications of Derivatives
• Calculus – Applications of the Integrals
• Calculus – Continuity and Differentiability
• Calculus – Differential Equations
• Calculus – Integrals
• Geometry – Area
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• Geometry – Introduction to Euclid’s Geometry
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• Geometry – Lines and Angles
• Geometry – Straight Lines
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• Linear Programming
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• Mensuration – Areas
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• Number Systems
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• Permutations and Combinations
• Probability
• Sequence and Series
• Sets and Functions
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• Trignometry – Height and Distance
• Trignometry – Identities
• Trignometry – Introduction

### Middle School Science

• Acids, Bases And Salts
• Air and Its Constituents
• Basic Biology
• Body Movements
• Carbon and Its Compounds
• Cell – Structure And Functions
• Changes Around Us
• Chemical Effects Of Electric Current
• Coal And Petroleum
• Combustion And Flame
• Components Of Food
• Conservation Of Plants And Animals
• Crop Production And Management
• Electric Current And Its Effects
• Electricity And Circuits
• Elements and Compounds
• Fibre To Fabric
• Food production and management
• Force And Pressure
• Forests: Our Lifeline
• Friction
• Fun With Magnets
• Garbage In, Garbage Out
• Getting To Know Plants
• Health and Hygiene
• Heat
• Hydrogen
• Life Processes: Nutrition in Animals and Plants
• Materials: Metals And Non-Metals
• Matter and Its States
• Metals and Non-metals
• Micro Organisms: Friend And Foe
• Motion And Measurement Of Distances
• Motion And Time
• Nutrition In Animals
• Nutrition In Plants
• Organization in Living Things
• Our Environment
• Physical And Chemical Changes
• Pollution and conservation
• Pollution Of Air And Water
• Reaching The Age Of Adolescence
• Reproduction In Animals
• Reproduction In Plants
• Respiration In Organisms
• Rocks and Minerals
• Separation Of Substances
• Simple Machines
• Soil
• Some Natural Phenomena
• Sorting Materials Into Groups
• Sound
• Stars And The Solar System
• Structure of Atom
• Synthetic Fibers And Plastics
• The Living Organisms And Their Surroundings
• Transfer of Heat
• Transformation of Substances
• Transportation In Animals And Plants
• Universe
• Waste-water Story
• Water: A Precious Resource
• Weather, Climate And Adaptations Of Animals To Climate
• Winds, Storms And Cyclones

### Middle School Math

• Area and Its Boundary
• Boxes and Sketches
• Data Handling
• Fun With Numbers
• Heavy and Light
• How Many
• Long And Short
• Mapping
• Measurement
• Money
• Multiplication and Factors
• Multiply and Divide
• Numbers
• Parts and Wholes
• Pattern Recognition
• Patterns
• Play With Patterns
• Rupees And Paise
• Shapes And Angles
• Shapes And Designs
• Shapes and Space
• Similarity
• Smart Charts
• Squares
• Subtraction
• Tables And Shares
• Tenths and Hundredths
• Time