Hello Simra Shah,

Inertia is the tendency of anything to remain unchanged.

In physics, it is the tendency of an object to not change its state of motion. Newton’s first law of motion qualitatively describes it:

“An object in rest will stay in rest and an object in motion will continue to move with a uniform velocity unless a force acts upon it.”

The concept of inertia is quantified in Newton’s second law of motion which gives us its relation to force and acceleration:

“The rate of change of momentum of an object is directly proportional to the force applied on it.”

Momentum is simply mass times velocity, For an object of constant mass, a force causes a change in velocity, however the amount of change is inversely proportional to amount of mass a body has. You see I have started talking about mass. In our world, the inertia and the mass of an object is the same, hence one term can be used in the place of other.

Thanku.

Hello Simra Shah,

I would like to tell you that Inertia is the resistance of the object to any change in its motion, including a change in direction. An object will stay still or keep moving at the same speed and in a straight line unless it is acted upon by an external unbalanced force.

For more detailed info about inertia, I would suggest you visit the below wiki thread.

The link for the same is:https://simple.wikipedia.org/wiki/Inertia

Hope this helps and all the very best!