Re: Is it necessary or helpful to teach work (W) in introductory HSphysics? (long)

["John S. Denker" <jsd@MONMOUTH.COM>]

chuck britton wrote:
> My philosophy would be to include work as the segue from Forces into
> Conservation of Energy. In fact, I have come to define work as the
> PROCESS of changing energy from one form into another form.

There are two or three issues there.

1a) As always, the concepts are of primary importance.  I agree that
concentrating on energy and energy-change processes is the right
way to go.

1b) I'm not sure that forces are the right foundation for building
an understanding of energy.  Sometimes but not necessarily always.
Perhaps my viewpoint is warped by my experience as a flight
instructor:  In the airplane you have an indication of potential
energy (altimeter etc.) which is very important, and you have an
indication of kinetic energy (airspeed indicator etc.) which is
very important ... and you have nothing of any imporance that
you can perceive in terms of force.  The law of the roller coaster
(9 feet per knot, per hundred knots) comes directly from conservation
of energy, not needing any mention of forces.

http://www.monmouth.com/~jsd/how/htm/energy.html#sec-energy-conversion

2) As always, terminology is of secondary importance.  There is a
strong (but not universal) consensus that "work" ought to denote
F dot dx.  If you "define work as the PROCESS of changing energy
from one form into another form" I'm not sure that's the right
terminology to go with the concept.  You forfeit any possibility
of having a work-KE theorem.  It might be good to warn students
that it's an unorthodox definition.