From: "JACK L. URETSKY (C) 1996; HEP DIV., ARGONNE NATIONAL LAB, ARGONNE, IL 60439" <JLU@hep.anl.gov>
Date: Wed, 17 Jul 1996 16:56:58 -0500 (CDT)
Hi all-
Apropos of Dan's remark:
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In the history of mechanics, Oresme and Buridan developed the idea of momentum
as the natural "quantity of motion" -- a quantity proportional to how much
stuff is moving and how fast it moves. Nicole Oresme worked around 1350
(250 years before Galileo, who also worked on the same idea before Newton).
Jean Buridan (50 years before as rector of the university of Paris) developed
the roots of Oresme's work on what was then called IMPETUS. Galileo and Newton
followed both.
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Some might find it helpful to review Galileo's discussion in
"Two New Sciences" (3d day, Naturally Accelerated Motion) of a stone
falling upon a stake, and estimating the momentum of the stone by the
distance that the stake is driven into the ground. This discussion
makes sense if the student is already convinced that all bodies that
fall from the same height (from rest) strike the ground with about the
same speed.
Regards,
Jack