Hi again, Brian, Together with Sherwood's article I am sending you a
related article by Leff and Mallinckrodt (AJP, February 1993). It is
also a lousy copy of a copy with the margin notes which are not mine.
There is no need to send them back; the microfiche collection of AJP is
in our library. The second article deals with "perpendicular" collisions
while the first one deals with "grazing" collisions.
A collision, as you certainly know, is not a slow thermodynamic process.
That is why the question "how slow is slow enough?" was posted. But nobody
responded. I know that this is a distraction from the main issue which is
"how to teach about work, heat and energy in the introductory courses?"
Should we continue introducing joule as a unit of work or should it be
introduced as a unit of energy (before the concepts of work and heat
are introduced)? How can this be done without being "too Aristotelian"?
Perhaps I should also say "too Platonic".
For work and heat we now have operational definitions, such c*m*dT, and
this helps (I think) with the very abstract concept of energy. Do we have
an alternative scientific way of INTRODUCING energy?