Re: Re: List Reborn

Chris

your comments treat speed the same as velocity. Velocity has a magnitude and a direction. If you change the direction, you change the velocity, but not necessarily the speed.

Cheers

steve
>
> From: Christopher Wright <chrisw@skypoint.com>
> Date: 2005/10/20 Thu PM 02:16:31 GMT+13:00
> To: <a href="/group/PipingDesign/post?postID=Sq5cRpSH3_d6N4YGqgeIJFytVT0uYebMi8T7mycYBsrm55Ai5zmeDFLc4MFacp69KF5wd1qotgQe2SGHniJkuEuzaCbE">PipingDesign@yahoogroups.com</a>
> Subject: Re: [PipingDesign] List Reborn
>
>
> 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
> chrisw@skypoint.com | this distance" (last words of Gen.
> .......................................| John Sedgwick, Spotsylvania
> 1864)
> <a href="http://www.skypoint.com/~chrisw/">http://www.skypoint.com/~chrisw/</a>
>
>
>
>
> =========================================
> PipingOffice - Excel Spreadsheets for Piping Calculations
> <a href="http://www.pipingoffice.us/">http://www.pipingoffice.us/</a>
> =========================================
> Main site: <a href="http://www.pipingdesign.com">http://www.pipingdesign.com</a>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
>
Received on Wed Oct 19 23:14:00 2005