Re: test problem

[Jack Uretsky <jlu@HEP.ANL.GOV>]

I also disfavor the use of the expression "total potential energy".  As
John D. keeps reminding us, potential energy is dependent upon your
arbitrary choice of zero.  One should only speak of changes in potential
energy.
                        Regards,
                                Jack


On Tue, 4 Dec 2001, John Mallinckrodt wrote:

> On Tue, 4 Dec 2001, Justin Parke wrote:
>
> > ...
> > Use conservation of energy to find the speed of the mass as it
> > passes through the midpoint (i.e. 12.5 cm from the origin)"
>
> I get the same answer that you do (2.6 m/s), but I think that the
> use of the word "midpoint" is highly misleading.  The midpoint of
> the oscillation (assuming that it somehow remains purely vertical,
> which would be very unlikely) is 20 cm from the origin--i.e., the
> equilibrium position. At *that* position the speed of the mass
> will be 2.8 m/s.  The real problem, however, is that for the
> oscillation to continue, the spring and mass will need to be
> constrained against "sproinging out" as the mass continues upward
> and compresses the spring by 15 cm.
>
> John Mallinckrodt      mailto:ajm@csupomona.edu
> Cal Poly Pomona          http://www.csupomona.edu/~ajm

--
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you, because that is what I must do.  Tonight it is only you and me, fish.
It is your strength against my intelligence.  It is a veritable potpourri
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                     <The 5-MINUTE ILIAD and Other Classics>