# Newton’s Three Laws of Motion – Physics

This post will teach us about Newton’s three Laws of Motion for class 11. The three laws given by Sir Isaac Newton were formulated in 1686. The Article starts with Newton’s first law of motion, also known as the law of inertia. The Law of inertia has three parts-

- Law of Enertia of Rest
- Law of Enertia of Motion
- Law of Enertia of Direction

Then We will talk about the second law of Motion which gives the information of the relationship between momentum and external force.

The last one is the third law of motion which reveals the concept of action-reaction force.

Note:- The article also provides you with the Numericals of each Law that you can practice and gain good marks in the examination. So let’s talk about the first law of motion called the law of inertia.

## Newton’s First Law of Motion – Law of Enertia

According to the First Law of Motion, the position of an object cannot change until an external force is applied to it. It is also known as the Law of Inertia. Now we will talk about inertia in different situations.

### Law of Inertia of Rest

According to the law of inertia of rest, If an object is in the condition of rest then the condition will not change until an external force is not applied to it.

### Law of Inertia of Motion

According to the law of inertia of motion, If an object is in motion then the position of an object does not change until an external force is not applied to it.

### Law on Inertia of Direction

According to the law of inertia of Direction, If an Object moves in a direction then the direction of an object does not change until an external force is applied to it.

## Newton’s Second Law of Motion

According to the second law of motion, the rate of change in momentum is equal to the external force is known as the law of Momentum.

### Derivation of Second Law of Motion

Let an object of (m) mass move with initial velocity (u) after (t) time it’s become (v) Velocity than:-

The initial momentum of an object = Pi = mu.

The Final momentum of an obejct = Pf = mv.

Change in Momentum = ΔP = Pi – Pf

= mv – mu

= m(v – u)

Rate of Change in Momentum = ΔP/t

ΔP/t = m(v-u)/t

ΔP/t = ma/t

ΔP/t = F

## Third Law of Motion – Action Reaction Law

According to the third law of Motion, Every action has an equal and opposite reaction known as the action-reaction law

Fba = -Fab

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