What is Intertia and Momentum?


I didn’t quite understand it in class….

In: Physics

Inertia is the tendency of things to keep the speed they have. You need a force to speed things up or slow them down.

Momentum puts that to a numerical value. It’s the velocity times mass. A force will slowly build up momentum in the direction it’s pointing. And you will need the same Force×Time in the other direction to stop it again.

In casual usage, both of them mean the way things that are moving keep moving.

In physics, momentum is mass times velocity. This is useful because it happens that when things bump into each other, their total momentum stays the same (when you allow opposite directions to cancel out i.e. treat it as a vector). That can be useful for calculating how things will move.