No time to look this up (64 papers to grade), but I seem to recall that one
can preserve the Work/Energy theorem in this case if one looks at what is
happening microscopically? Maybe akin to the fact that any horizontal
surface must deform slightly to hold up a mass placed on that surface? Just
wondering.
Rick [Who really doesn't have a problem with the fixed observer saying that
static friction is the force that causes the displacement of the crate.]
----- Original Message -----
From: <carmelo@pacific.net.sg>
Some physicists proposed that 'static friction' to be
named "shear adhesion" instead. You may consider transfer of "Coulomb
energy" from the microscopic view?