I am sure we all have our own methods for explaining why calling `g' the
acceleration due to gravity is inappropriate. I would suggest defining
weight in the usual way and then calling `g' the weight per kg (or lb, if
you must). Of course, you then have to comment on common usage and in the
process you can (once circular motion has been covered) comment on how and
why g varies from equator to poles. A few observations about the earth's
dense core and its oblateness might suggest that there is a bit more to
mechanics than inclined planes and pulleys. Similar discussions can be
introduced elsewhere (plumb lines near mountains and the like). For some
students, a useful seed may be planted while for others there will be the
predictable `obviously not test material' reaction. Even for these latter,
some will recall your comments the next time they encounter these ideas - in
a subsequent course or in reading Scientific American or other magazines.
The seed has at least been cast - whether it falls on arable soil or not is
rarely within our control.
Lew
Lew Haddad
Physics Department
Dawson College
3040 Sherbrooke W.
Montreal QC
H3Z 1A4