[Phys-L] Re: TPT article on momentum & reference frames

[betwys1 at SBCGLOBAL.NET (Brian Whatcott)]

At 03:27 PM 10/2/2005, Antti, you wrote:
> Hi all,
>
> I got my copy of the October issue of The Physics Teacher a few
> days ago; there was a quite interesting article
> "When is momentum conserved and what about car crashes
> in Virginia?". However, it seems to me that he made a small (?)
> mistake when writing about an orbiting shuttle:
>
> "Astronauts inside the shuttle would find that momentum is
> conserved for collisions of objects in *their* accelerated
> noninertial reference frame". (the emphasis added by me)
>
> I have  thought that the frame *inside* the shuttle would be
> a free float frame (as Spacetime Physics by Taylor & Wheeler
> put it). Hence it would be a (local) inertial frame instead
> of "accelerated noninertial reference frame". Of course,
> the shuttle is accelerating as judged from the reference
> frame fixed to the Earth.
>
>
> Regards,
>
> Antti
>
> Antti Savinainen, Ph.D., B.Ed.
> Senior Lecturer in Physics and Mathematics
> Kuopio Lyseo High School
> Finland
> E-mail: <antti.savinainen@kuopio.fi>
> Website: <http://kotisivu.mtv3.fi/physics/>

Joe Kolecki (NASA) seems to take the Physics Teacher article's author's side
rather than Taylor or Wheeler's...
See:
    <http://www.grc.nasa.gov/WWW/K-12/Numbers/Math/Mathematical_Thinking/field_equations.htm>



Brian Whatcott    Altus OK    Eureka!