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Re: CONSERVATION OF ENERGY/INTERNET IN EDUCATION



It's this sort of dialogue that makes internet important to me in education.
Frankly, I would not have a chance to learn these nuances any other way
since I am the soul physicist at my institution and relatively new to the
game. Much of what we learn about physics and teaching comes from the on the
job training and conversations with more experienced colleagues. These
experiences come hard for community college and high school faculty who do
not have contact with other faculty in their discipline on a daily (or
evenly yeraly) basis.

Oh and I never spit on the floor without a really good reason.


While waiting for clarifications about the name for c*m*dT let me refer
to what Leigh Palmer <palmer@sfu.ca> wrote yesterday. Repying to:

.... I was asking how a common statemet "energy = ability to do work"
should be interpreted. Or what does it mean that "work by friction is
done at the expense of kinetic energy"?

Leigh wrote:

The statement "energy = ability to do work" is at best meaningless.
The second statement is not useful; perhaps it is wrong. .... Certainly
heat plays no role in the process; no energy is transferred between the
blocks impelled by temperature differences. If you say "but heat must
be generated by the process of friction" you will be using the term
"heat" with its vulgar meaning, not the technical meaning we employ
in thermodynamics.

Let us wait for the consensus about the wording for c*m*dT. I was asking
for a clarification of the meaning of two common phrases: "work at the
expense of energy" and "energy as an ability to do work". Are these phrases
acceptable? Why yes? why no? The answer was:

No. As to why, answer the question "Why is it unacceptable to spit on
the floor?" Acceptability is a matter of convention in both cases. ....
You have defined the problem almost well enough. Please reformulate
it carefully and ask a physical rather than a linguistic question
(e.g. "What temperature rise is to be expected?" rather than "Can we
say that...?").

Linguistic questions are important. Just put yourself in a situation of a
typical high school teacher. My guess is that at least 50% those who teach
physics do not even have an undergraduate degree in it. They work hard to
keep up with the discipline but everything has its limitations. Please do
not start another thread on this subject now. But keep in mind that a lot
of high school teachers, and many college teachers, take what they read
much less critically than we, phys-L-ers. A typical teacher does want to
have clear "true or false" answers about what is and what is not acceptable,
according to conventions of our discipline.

Linguistic is terminolgy; it can not be separated from formalism. I hope
more people will participate in this discussion about proper (acceptable)
uses of thermodynamic terms in elementary physics.
Ludwik Kowalski
P.S.
Why it is not acceptable to spit on the floor? This question has nothing
to do with science. How can you compare it with serious questions about
verbal nuances of the first law?

R. Allen Shotwell
Chair, Science and Math
Ivy Tech State College
Terre Haute, IN