I do think it is much more useful to teach students about simple
machines than it is to teach them about the compositions of
protons and neutrons. The problem in teaching machines arises when
one works with taxonomy, e.g. the definition of a fifth class
lever, or gets hung up on the minimum spanning set of fundamental
simple machines necessary to represent all complex machines.
I would teach the concepts of mechanical impedance and impedance
matching in a high school physics course, and I would not miss the
opportunity to introduce my students to a differential hoist in
the laboratory session. They may have to go down to the auto shop
to play with one, but no physicist should ever feel his education
is complete if he hasn't done so. They do neat things with
standing waves in chains under tension, too. I also think that
physicists should pull stumps with a come-along, and that they
should have intimate knowledge of the workings of their bicycles.
Older physicists should have disassembled a Sturmey-Archer* three
speed hub. PhD physicists should have reassembled one correctly.
While it is not a simple machine, I think that there is good moral
training in rebuilding a fairly sophisticated carburetor, too.
Fluid mechanics is also an excellent, accessible area which
requires little mathematical sophistication in its earlier results
(don't mess with "explaining" airfoil lift or curve balls, but
Pitot tubes are OK).
I think you are probably right; simple machines would make a good
contribution to the young scientist's education.
Leigh
*I just checked - they have a web site! Younger physicists are
now encouraged to seek out this marvel. They still make the AW
3 speed hub, but there's no mention of the SW.