According to an old book on electrostatics the coefficient of
kinetic friction is not always proportional to the load, N. For
Al on steel f=mu*N for any N (mu=1.2). But for Cu on Cu this
is true only when the load is due to at least 100 grams (mu=1.8).
Below this: mu=0.4 at 0.1 grams, 0.7 at 1 gram and 1.5 at 10 grams.
Reading from the graph (a lot of data points and a smooth line ).
Just another illustration of the limited validity of our model.
I did not receive phys-L messages since Thursday; something was
not working during the transition; Dick Smith fixed it today.
If you posted something related to the IONS/dielectrics thread
please send me your message (in private), if you can. The last
one I received was from Bob S.