Re: What's wrong with this?

----- Original Message -----
From: "Glenn Morton" <glennmorton@entouch.net>
To: "'Ted Davis'" <tdavis@messiah.edu>; <asa@calvin.edu>; <gmurphy@raex.com>
Sent: Monday, June 21, 2004 8:00 PM
Subject: RE: What's wrong with this?

> Darn, you got the gold star before me. But one addition. It was only in
> free fall when it was on a geodesic path outside of the part of the
> atmosphere where enough atmospheric density could cause significant
> drag.
>
> > -----Original Message-----
> > From: asa-owner@lists.calvin.edu
> > [mailto:asa-owner@lists.calvin.edu] On Behalf Of Ted Davis
> > Sent: Monday, June 21, 2004 6:40 PM
> > To: asa@calvin.edu; gmurphy@raex.com
> > Subject: Re: What's wrong with this?
> >
> >
> > If this is a quiz, George, the answer is: It isn't
> > weightless, it's in free fall. Like the moon around the
> > earth, or the earth around the sun.
> >
> > Do I get a gold star or my pick of the toy bag??

Ted & Glenn -
        Not exactly. Objects in free fall _are_ weightless because in a
coordinate frame moving with them the gravitational acceleration has been
transformed away locally. It doesn't matter how high you are - you're
weightless (except for the effects of air resistance) when you jump off the
high dive. Astronauts train for weightlessness - or at least they used to -
in planes that are in free fall (though perhaps moving upward &
horizontally - on a parabolic path) for a fraction of a minute.

Shalom
George
http://web.raex.com/~gmurphy/
Received on Mon Jun 21 20:46:14 2004