# Understanding momentum concept

Hello

Please, if you UNDERSTAND WHAT IS MOMENTUM, tell me.

I want to know, why do I need momentum, why was this concept introduced. If I were an ancient scientist, what's the problem that faced me in absence of such concept, that lead me to devising it, and at which basis did I choose my independent variables, mass and velocity.

## Answers and Replies

I've forgot to say:

Mu readings have lead me that the concept was introduced in order to account for the uniform motion (assume it's space with no resistances), that a body makes although the physical interaction causing it to move disappeared.

I still don't get it, I think the answer is simply because that body has a kinetic energy! and energy is conserved, there's no resistance, no consumption, let the body move because of its energy.. why momentum?? why to think that energy interpretation is not enough, and that I need another sufficiently explaining concept?

Doc Al
Mentor
I still don't get it, I think the answer is simply because that body has a kinetic energy! and energy is conserved, there's no resistance, no consumption, let the body move because of its energy.. why momentum?? why to think that energy interpretation is not enough, and that I need another sufficiently explaining concept?
There are many cases where mechanical energy is not conserved, yet momentum is

Momentum is also a vector quantity, kinetic energy is not.

Let's say it's conserved, WHY to introduce a new concept? is just because of the scalar nature of energy quantities?

Doc Al
Mentor
Let's say it's conserved, WHY to introduce a new concept?
Any time you can introduce a new quantity that is conserved it expands your power to understand the world. Take the simplest case: A ball collides with another at rest. Assuming kinetic energy is conserved doesn't allow you to predict what will happen. Adding momentum conservation does.

That's acceptable :D

Thanks ALOT :)