I'll tell you what irritates me, Jon, and that is people who are so certain of their own correctness that, when vexed by contradiction, they begin accusing their "antagonist" of saying things they did not say, believing things they do not espouse and generally behaving in an irrational, hysterical manner. I am a working professional in the field of terminal ballistics. I do this stuff every day of my life and I promise you that I have a better grasp of the course of the last 300 years of science than you suggest. I have not made railing accusations against you at any stage of this argument and I won't do it now, but I am done with the argument.

[This message has been edited by Harald (edited 01-20-2002).]

JonA,

I am an art teacher and even I can figure out that momentum and kinetic energy are related! Your statements about the different systems having kinetic energy, but no momentum are totally WRONG!

So everybody understands.

Momentum = mass X velocity

Kinetic Energy = 1/2 X mass X velocity X velocity

So basically as long as you have a mass and it is moving you have both momentum and kinetic energy.

I do not know if Harald and Todd E are full of it or not because those two are way over my head, but JonA is completely wrong.
Casey

CASEY,

You missed the point that momentum is a vector quantity--it has both magnitude and direction.

In the example I gave above with two balls approaching each other, one would have a positive velocity and one would have a negative velocity on the same coordinate system. The sum of their momentum is zero.

Velocity is squared when you figure the energy for each, ensuring positive values for both.

Harald, sorry if I hurt your feelings.

Fair enough.