Re: Why work before energy in texts

[Rick Tarara <rtarara@SAINTMARYS.EDU>]

----- Original Message -----
From: "kowalskil" <kowalskil@MAIL.MONTCLAIR.EDU>
> 3) We are not discussing zero temperature oscillators,
> or other advanced QM topics. We are discussing an
> introductory physics sequence.

This is a very important point.  In most of our Phys-L threads, what starts
out to be a discussion of a topic AS presented in intro texts, usually
blossoms into post graduate level quibbling.  There are fundamentally 2
groups of physics education 'consumers', the physics majors and all the
others.  Within the others, one can subdivide again, into 'general
education' students, and science/engineering students.    At the
college/university level, the intro physics course is the terminal physics
course for a very large percentage of the students (95%-??).  The textbooks
used in these intro courses are the same for both the majors and the others
(at least at the calc level) and must reflect the fact that the majority of
users are taking their last course in physics.  This fact, I'm sure, colors
the presentation and content of these texts.  Serway for Physics Majors
might well be a different text than Serway for Scientists and Engineers.  I
think it has been accepted that the incomplete, oversimplified, and
sometimes 'wrong' presentations in the intro texts will be completed,
expanded, and corrected in higher level physics major's courses.

The point here (I'm rambling) is that we have to be very aware of the
audience when talking about major changes in the
curriculum/content/pedagogy.  What might be an ideal ordering of topics for
a Physics major might not work well at all for a Bio major in an algebra
level course.  The 'nits' that are constantly picked here on the list are
usually meaningless for a 'general education' class.  I would suggest that
if _some_ of the discussions here were followed in teaching such a class, it
would be a disaster.  This is what makes teaching physics so difficult--you
can't necessarily teach work/energy/forces/weight/etc. the same at all of
these course levels.  It is not JUST a matter of math level--it is much more
complicated.  Energy before work might be successful with one group but not
another.  Testing new pedagogy and/or curricula is also complex.  What works
for the 'creator' of the teaching technique or subject order may not work
for others.

[I just got caught with my general ed class where this year I vowed to
follow the order of their book--trying to get them to read it--but their
book does momentum before energy.  The problem is that the book only deals
with conservation of momentum during collisions but I want to do elastic
collisions (to setup a lab) and hit the middle of lecture yesterday
realizing that we hadn't covered kinetic energy.  It might help if _I_
actually read the book.  ;-(   ]

Rick

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Richard W. Tarara
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Saint Mary's College
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rtarara@saintmarys.edu

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