Hi!
I have been following this discussion and saw very good comments
by Rick, David, Leigh, Karl and others. All of us who teach know the
problem of the too short blanket: your feet or your upper chest are
left uncovered. So, let's proceed scientifically and list a set of
tentative axioms for teaching.
1. We should introduce the precise terminology of common use in physics.
It is important to discuss the difference with common language, where
for example effort = force = work = power.
2. If some jerks give sexual meaning to almost every term, this is no valid
reason to proscribe its correct use in physics.
3. One of the most fundamental goals is to introduce (correctly) new
concepts and get students to be familiar with them. Examples: vector
quantities, fields, waves etc. To DEFINE these is usually simple, but
to familiarize students with them takes a lot of time and insistence.
4. Anything students learn should get to the point where they "under-
stand" it, i.e. when they have a clear idea of when and how they can
apply it. If you don't reach this point, the whole thing is a waste
of time and should better be skipped.
5. Studying physics goes necessarily from the simple to the complex:
you can't understand complex processes if you don't understand the
simple components of them.
6. Our understanding of any real process is always incomplete (all matter
is really cpmposed by atoms and subatomic particles, all laws are really
from quantum mechanics and relativity, etc.). Hwence it is futile to try to
make students undertand everything "completely" and perfectly "correctly".
The "understanding" should be in the context and approximation we are
talking in each case.
7. Students should get comfortable using (approximate) models as acceptable
descriptions of real processes. We may for example argue on the basis
of point-masses, solids and fluids as continuous, friction as being
negligeable etc., even knowing that all of this is not really true.
Students should also realize the resulting limitations of correspondent
conclusions.
We could XNadd more, but let it be enough for today. Bye, Emilio