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Re: ENERGY WITH Q



Jim Green wrote: "We _define_ Int F*ds as work."

Carl E. Mungan replied: "No, you just defined pseudowork."

Recognizing that work and pseudowork are two different
concepts is useful. But why not to say that F*ds is work
and W from the first law is "pseudowork?" We teach about
F*ds before we teach the First Law. It would be silly to
introduce the name "pseudowork" to students who are not
familiar with the concept of work.

Compare this with using the term pseudo science without
first explaining what science is. The prefix pseudo is
ridiculous, unless the word with which it is linked has
a meaning. The physical quantity F*ds has been called
work for very long time; what kind of pedagogical
benefit can be derived from renaming it?
Ludwik Kowalski







Some of this work we call PE and we lump the PE and the KE together -- This
is not always helpful in an intro class.

Give me an example where it's not helpful.

Thus the work done on the system = - the work done on the applicator.

There is indeed such a law for thermodynamic work.
There is however no such law for pseudowork, as many have already pointed out.

Now some on this list will want to use "enhanced" language but this is
quite adequate for an intro class -- and beyond.

And you have just given an excellent demonstration of why such
enhancements are very much needed.

John Denker wrote:

I've been doing a survey, talking to physicists. Not physics
teachers, but people who do physics research for a living.
-- I ask them for the technical definition of "work".
100% of them answer "Force dot distance".
-- I ask them for the corresponding definition of "pseudowork".
100% of them give me funny looks.
0% have ever heard of the term before.
(Nearly 100% of them fall back to a non-technical
definition: pseudowork is what management does :-)

I'm shocked that you of all people would stoop to this. Haven't you
said before that physics is not decided by polls?

Go back to your physics researchers. Ask them if if they know what
Newton's second law is. Ask them if they can integrate it over the
displacement of the center of mass of an object (whether rigid or
not) and can relate that to its bulk translational kinetic energy.
Tell them, "Oh so you do you know what it is."

The fact that the name "pseudowork" is a relatively new term is moot.
I can probably find other new terms in the physics education
community that *our* physics research friends also have not heard of.
Does that mean they're all useless? Is introductory physics now so
well explained that no innovations in our lexicon and texts are
needed?

ps: I don't fully appreciate the fact that you appeal to those who
"do physics research for a living" and call them "physicists." The
rest of us are not physicists? Teaching has disconnected us from real
physics? We no longer do physics research for a living even as
teacher scholars?
--
Carl E. Mungan, Asst. Prof. of Physics 410-293-6680 (O) -3729 (F)
U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5026
mungan@usna.edu http://physics.usna.edu/physics/faculty/mungan/