Hi everybody!

 

As you may define "Force" as a "push or a pull", then how would you go about defining momentum in the same way.

 

Please don't use "mass*velocity" stuff, I've read it thousands of times in my textbook and it doesn't really explain the actual meaning of momentum.

 

Thx.

Tendancy to resist change in motion?

I'm not sure what you're looking for here. Moving things have momentum, because it takes a force applied to them to change their velocity.

The conserved current associated with a translation symmetry

Please don't use "mass*velocity" stuff, I've read it thousands of times in my textbook and it doesn't really explain the actual meaning of momentum.

 

But thats the actual definition of momentum.

The quantity of motion.

Hi everybody!

 

As you may define "Force" as a "push or a pull"' date=' then how would you go about defining momentum in the same way.

 

Please don't use "mass*velocity" stuff, I've read it thousands of times in my textbook and it doesn't really explain the actual meaning of momentum.

 

Thx.[/quote']

Momentum is the product of time, weight AND direction. Put simply, an object falling for ten seconds will have more potential energy than the same object falling for five seconds. Hope this helps.

For a moving object:

Something twice as heavy is twice as hard to slow down.

Something twice as fast is twice as hard to slow down.

 

So momentum is directly proportional to both mass and velocity. This means that mass*velocity = momentum.

Momentum is the product of time, weight AND direction. Put simply, an object falling for ten seconds will have more potential energy than the same object falling for five seconds. Hope this helps.

 

An object falling has less potential energy the longer it falls, and PE is not momentum.

For a moving object:

Something twice as heavy is twice as hard to slow down.

Something twice as fast is twice as hard to slow down.

 

So momentum is directly proportional to both mass and velocity. This means that mass*velocity = momentum.

 

I'd change that to "bring to a stop" instead of "slow down."

I have already given you the correct technical definition (seriously!).

 

For a particle of mass m travelling with velocity [math]\vec{v}[/math], this becomes [math]\vec{p} = \frac{1}{\sqrt{1-v^2/c^2}} m \vec{v}[/math].

 

If you want to link it to force, then force is the rate of change of momentum.

The conserved current associated with a translation symmetry

 

Buggery, beaten to it.

The far more successful antecedent of Joementum.

aight. now, I understand that momentum in a mass in motion, and it's the quantity of motion. But the question that is still confusing me is why on Earth we need to study momentum? What makes a difference?

Well, without momentum collisions would not happen because objects would stop with little force. It is very important.

the energy a mass has left over after a direct force has finished with it.

Those who does not understand the language of mathematics are illiterated to read the book of universe. ~~Galileo

Well you know that force is "a push or a pull,"

so in terms of force,

[math]p=\int{F}·dt[/math]

impulse is the integral of force with respect to time not momentum.

Those who does not understand the language of mathematics are illiterated to read the book of universe. ~~Galileo

Does that include Farady, who never wrote down an equation??

Momentum can be defined as "mass in motion." All objects have mass; so if an object is moving, then it has momentum - it has its mass in motion. The amount of momentum which an object has is dependent upon two variables: how much stuff is moving and how fast the stuff is moving. Momentum depends upon the variables mass and velocity.

If I understand this correctly, Einstein's theory of relativity can be used to describe and ultimately define momentum. Doesn’t time have something to do with momentum? - Without time you cannot properly measure velocity, or even motion. Am I missing something.... but without time...how do you measure speed? Without speed how do you define momentum? Obviously momentum is relative to mass, speed and friction. Am I a confused SOB or what?

 

Iv heard that if you catch up to the speed of light it would no longer exist!!!? It will seem as the light is not moving...but at a stand still...but if light is at a stand still you can’t see it? WTF!

 

Or what about that experiment where you take a laser beam, and shine it though a vertical slit onto a wall. When the slit is open, the laser beam will appear round on the wall, then as you narrow the slit, the sides of the beam begin to narrow (as expected) and the light becomes oval shaped until you close the slit so far that all you see is the "wave" of the light and it does not end up being a tiny vertical slit of light, but rather it spreads our horizontally.

 

I’m sorry if I didn’t explain that good enough, but if some of you know about what I’m talking about and care to explain this phenomena to me, id like that a lot! Its has something to do with quantum theory that light is not light until you see it...or something!...I'm just starting to study physics and science in general, so these ideas fascinate me but I’m unable to fully grasp them yet.

basically you study momentum because it is conservative in some systems and so it makes the mathematics easier.

If I understand this correctly' date=' Einstein's theory of relativity can be used to describe and ultimately define momentum. Doesn’t time have something to do with momentum? - Without time you cannot properly measure velocity, or even motion. Am I missing something.... but without time...how do you measure speed? Without speed how do you define momentum? Obviously momentum is relative to mass, speed and friction. Am I a confused SOB or what?

 

Iv heard that if you catch up to the speed of light it would no longer exist!!!? It will seem as the light is not moving...but at a stand still...but if light is at a stand still you can’t see it? WTF!

 

Or what about that experiment where you take a laser beam, and shine it though a vertical slit onto a wall. When the slit is open, the laser beam will appear round on the wall, then as you narrow the slit, the sides of the beam begin to narrow (as expected) and the light becomes oval shaped until you close the slit so far that all you see is the "wave" of the light and it does not end up being a tiny vertical slit of light, but rather it spreads our horizontally.

 

I’m sorry if I didn’t explain that good enough, but if some of you know about what I’m talking about and care to explain this phenomena to me, id like that a lot! Its has something to do with quantum theory that light is not light until you see it...or something!...I'm just starting to study physics and science in general, so these ideas fascinate me but I’m unable to fully grasp them yet.[/quote']

 

This seems to me to be a good topic to start another thread with.

What is the difference between momentum and energy ?