Re: The Olympics

[Joel Rauber <Joel_Rauber@SDSTATE.EDU>]

David,
How significant is the "bi" part of your comment?  Wouldn't the components
be individually conserved, even if it were a regular vector;  As in, Linear
Momentum components in the absence of the corresponding component of net
Force?

Joel Rauber
Joel_Rauber@sdstate.edu


> -----Original Message-----
> From: phys-l@lists.nau.edu: Forum for Physics Educators
> [mailto:PHYS-L@lists.nau.edu]
> Sent: Wednesday, September 27, 2000 2:30 PM
> To: PHYS-L@lists.nau.edu
> Subject: Re: The Olympics
>
>
>
> Regarding Rick T's comment:
>
> > Perhaps one of the confusions here (at least for me) is that
> looking at
> > Bruce's link (below) it is now clear that the claim is NOT that the
> > gymnast/diver imparts NO angular momentum on takeoff, only
> that they often
> > impart no angular momentum around the vertical axis--that is, they do
> impart
> > AM around a horizontal axis perpendicular to their direction
> of motion.
> > That this can be converted to AM around other axes without
> changing the
> > overall vector AM is what is apparently not well understood
> but seems to
> > involve techniques like the 'tilt twist'.  These maneuvers
> would then be a
> > combination of imparted AM from the jump and reorientation
> of the body by
> > twisting different parts--just right.
>
> Total angular momentum is a (bi)vector.  As such all of its components
> are *individually conserved* in the absence of corresponding
> components
> of the externally applied net torque.
>
> David Bowman
> David_Bowman@georgetowncollege.edu