Re: Work/Energy theorem ?

["Donald E. Simanek" <dsimanek@eagle.lhup.edu>]

On Tue, 18 Mar 1997, Leigh Palmer wrote:

> ...and let me add my compliments! A farting fly can achieve the power*
> of a railroad locomotive when seen to emit while moving sufficiently
> rapidly! I have to teach my students that energy is insubstantial; that
> there is no such thing as "pure energy". I wish they had not picked up
> that particular concept. Caloric does not belong in a modern curriculum.

I agree totally on the "energy as stuff" issue. But I defer on the farting
fly till I get a response from the biologist I forwarded this to, asking
him whether flies *can* fart, and what velocity and mass might be expected
in such a fart. (We have to be careful on these science details.) 

> If you want to see energy done well, see Feynman Volume 1 on the
> conservation of energy. He has a parable (Dennis and his blocks) which,
> as usual, is conceptually right on the money. I always read this
> section verbatim to my introductory students, knowing full well they
> will not look it up if I recommend it**. The math should not scare
> even those delicate sensibilities Hewitt tries to protect. Try it;
> you'll like it! Please compare it to Hewitt and let us know what you
> think.
>
> **But a physics teacher who hasn't read it surely will look it up.

Leigh, you are being optimistic here. After all these years in the ed-biz
you should know better. I suspect most high school physics teachers (at
least in the U.S.) do not have Feynan's _Lectures in Physics_ in their
school library, or in their personal library. I'm only guessing here;
maybe we should take a survey of what *good* library resources are
available to high school teachers. My suspicion is that those resources
don't go beyond typical high school texts, a few "popular" science trade
books, some demonstration collections and perhaps some college texts the
teacher used years ago. I doubt that even the majority of teachers
subscribe to "The Physics Teacher" and/or the "American Journal of
Physics", and don't have these in their school libraries either. The folks
on this disussion group probably do, but they aren't typical of the entire
population of physics teachers. Many must cope with shabby school
libraries and may not even have interent access.

	-- Donald

......................................................................
Dr. Donald E. Simanek                            Office: 717-893-2079
Prof. of Physics                    Internet: dsimanek@eagle.lhup.edu
Lock Haven University, Lock Haven, PA. 17745          CIS: 73147,2166 
Home page: http://www.lhup.edu/~dsimanek            FAX: 717-893-2047
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