OK. Energy is proportional to velocity squared. If you double the velocity, you have four times as much energy as in the first case. Also the direction of the motion is not important. For example, a ball moving to the right has a certain amount of energy and a second one moving to the left with the same mass and velocity will have the same amount as well. Energy adds, so you have two times the amount contained within one.
Momentum is proportional to velocity directly. The direction of the movement is important since momentum is a vector quantity, unlike energy. The two ball case above results in a net momentum for the system of zero. The two vectors are equal and point in opposite directions so they cancel. Energy and momentum require different rules of behavior and can not be interchanged. Dave -----Original Message----- From: H Veeder <[email protected]> To: vortex-l <[email protected]> Sent: Sun, Feb 9, 2014 5:47 pm Subject: [Vo]:Energy and momentum / was RAR On Sun, Feb 9, 2014 at 5:13 PM, David Roberson <[email protected]> wrote: You need to be thinking of momentum instead of energy Harry. The two are not interchangeable. Dave Let's explore this separation between energy and momentum. harry

