🚀 go-pugleaf

This may seem strange in reference to the question, but it may
help in some ways.  I explain to my students that there are
"Orders of Conservation Laws" with "Conservation of Energy"
being the top one.  All others are subservient to it.  The
analogy I use is that the US Constitution is the "top law" of
the land, state constitutions are below it, county below it and
so on down the line.
Similarly, Conservation of Energy is the top law of physics (at
least in the Newtonian world) and everything else
conservation-wise is below it.
Thus, it is easy to conserve momentum, but it cannot happen
unless energy is also conserved.  This also gives some room to
expand on both rotational and rectilinear motion and the
conservation is those, particularly when a student has observed
that a wheel that has rolled down a hill does not have the same
rectilinear motion (energywise) at the bottom as it did
gravitational potential at the top.  When the angular velocity
is computed with the concommitant energies and momenta, the
answer gets better.  Then we can get some idea of how
comprehensive the conservation of energy law is.
Hope this clears up a bit.  I know it is a strange way of
putting it, but when you come from the state that authored the
constitution and declaration, you get kind of philosophical
about the whole ugly mess.
--
Dave Button -- Osbourn Park High School
Manassas, VA 22111  There is no try, there is only do and not do.  Yoda