🚀 go-pugleaf

In reply to the gentleman who asked for help regarding the forces between
charges, I would like to add my proverbial two cents worth.  Electrical
forces present a particular challenge since they are either attractive or
repulsive, but I think that part of the groundwork which can lead to
understanding this complication is laid in mechanics.  In particular, we
must stress the interactive aspect of Newton's third law- that is, forces
come in equal but opposite pairs.  I take a bit of liberty to stress the
"active" and "reactive" aspects of these laws by leaning against a wall and
describing the pair of forces involved; if I weren't "actively" pushing
against that wall, it wouldn't react.  As I stand on the floor, I point out
that it "reactively" flexes a bit due to my weight.  I think that this
stress on force pairs, the only way forces _can_ be presented, is absolutely
essential, but note to students that it is perhaps a strange way to think
about things because it is necessary for the mathematics to "work out".
<<Joe>>
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   Joseph F. McLaughlin, Physics
   jxm39.psuvm.psu.edu
   Brentwood High School
   Brentwood (Pittsburgh), PA