From: Marc Afifi (marc_afifi@yahoo.com)
Date: Sat Dec 11 1999 - 09:46:31 PST
Message-ID: <19991211174631.16149.qmail@web210.mail.yahoo.com> Date: Sat, 11 Dec 1999 09:46:31 -0800 (PST) From: Marc Afifi <marc_afifi@yahoo.com> Subject: Re: pinhole Hewitt and circular motion
Thanks Paul,
As ususal, you made something click.
How about if we say that the direction the moon moves
is always perpendicular to the force of gravity
because the force is continually changing direction as
well since gravity is a radial force? Then clearly the
motion of the moon is never in the direction of the
force and consequently there is no instantaneous
physical work done. However, there is a change in the
direction and it is certainly caused by the force of
gravity, so what do we call that if not work? Or is
this where Ron's explanation using general relativity
is more appropriate? In other words, the moon goes
around the Earth because, by nature, it does? In this
case, could we say that the force of gravity does work
on the space between the Earth and the moon, or is
that a ridiculous misuse of both the term work and
gravity?
By the way, it was great to see you at the Asilomar
Math Conference. Sorry I couldn't attend the reception
afterwards, but Lila was passed out after long day of
running around counting and singing her ABCs so we
took her home. I look forward to next year.
-Marc
=====
Marc Afifi
Chemistry, Physics, Marine Science
Pacific Grove High School
Pacific Grove, CA
http://www.pghs.org/staff/afifi/d5hp.html
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