I read today Carl Mungan's excellent article on work-energy relationships (TPT January 2005). Congratulations, Carl!
I was pleased to note that Carl acknowledged many Phys-L members.
Well, I have a question on a point made in the article. Carl wrote:
"Static friction does not change the thermal portion
of the spool, in striking constrats to kinetic friction
on a sliding object. This is *not* a consequence of
the fact that static friction does zero particle work!"
Then Carl gives two examples which support this point but he does not explain the reason why "static friction does not change the thermal portion of the spool". I see that Carl's point is clearly valid but I don't know why
(I would have thought that it is because static friction does zero work...). What is the physical reason, then?