Re: List Reborn

From: <Christopher>
Date: Wed Oct 19 2005 - 21:16:00 EDT

On Oct 19, 2005, at 5:13 PM, Geoff Stone DD&D Australia wrote:

> I understand the logic here but I think Steve was right. Just look at
> the units of momentum and energy. Change in momentum is actually
> impact not change in energy.

Physically a change in momentum isn't energy, but a change in momentum produces a change in energy as I showed. You can't change momentum without changing either mass or velocity, and if you change either mass or velocity you also change the kinetic energy.

The relationship is what I showed (if mass is constant):

ÆKE = mvÆv and the change in momentum, ÆP= mÆv. So ÆKE = vÆP. You can't say that the change in momentum equals the change in energy, but you can say that the change in kinetic energy equals the instantaneous velocity times the change in momentum.

Christopher Wright P.E. |"They couldn't hit an elephant at <a href="/group/PipingDesign/post?postID=WLjangGtXu1NdwsOV17mm10jeb0oX8mX7trFEYUywfgcWfx_UEnlff4PgmqFwA0ypxudVuy7_Xo3Kkv5WFM">chrisw@skypoint.com</a> | this distance" (last words of Gen.

.......................................| John Sedgwick, Spotsylvania

1864)
<a href="http://www.skypoint.com/~chrisw/">http://www.skypoint.com/~chrisw/</a> Received on Wed Oct 19 21:16:00 2005