# Newton’s first law of motion ## Introduction

We have learned Newton’s three laws of motion in depth in our previous article. If you want to view that article do get an idea of all the laws then click here. In this article, we will try to understand Newton’s first law in-depth.

## The first law

Newton’s first law of motion is all about “inertia”. But, what is this inertia? The word “inertia” is derived from the latin word “iners” meaning laziness.
Now, inertia is a very simple concept and crucial to understanding the first law. In physics, inertia is the “inability of a body to change its state on its own”. Here, state refers to either a body’s state of rest or its state of motion. What the above statement said is that If a body is in motion then it will stay in motion and if the body is at rest then it will stay at rest. Now that we have a basic grasp on the concept of inertia, we can proceed to understand the statement.

Statement- Every object stays in its state of rest or in its state of uniform motion along a straight line unless and until acted upon by an external unbalanced force.

explanation- The above statement simply means that if you have an object at rest it will forever stay at rest unless and an object in uniform linear motion will always stay in linear uniform motion unless and until an external force compels the body to change that state.

For example, this football will stay at rest forever unless and until someone kicks it.

The first law is so related to inertia that is has been dubbed the “law of inertia”.

Inertia is a simple but big topic. We have so much to talk about it that we are writing a whole another article on it. To view it, click here.