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Re: 2 pi i = 0



Or finally decide what g means?

Is it 'Can of Worms' time again?
What POSSIBLE meaning could g have except for
'the weight in newtons that registers on a spring scale
when a standard kg is hung therefrom'?

g should always be stated as a newtons / kilogram
conversion factor.

Finding the associated acceleration is an exercise in Newton's #2.



This is precisely the formulation of g that was proposed in the last TPT
review of HS texts, Cliff Schwartz editor. The authors castigated the usual
formulation g=9.8 m/s^2. This debate is not new to this list, as that
review was in the mid 90s.

The authors of Minds on Physics, UMass Amherst UMPERG Leonard, Mestre,
Dufresne, & Gerace also suggest the g=9.8 N/kg formulation. Their reason is
that student are extremely confused by the traditional definition, but seem
to understand the "conversion factor" definition, according to their
research. This should not be surprising. The idea of calculating force on
a stationary body by using an acceleration does not make sense to most HS or
first year college students.

While it is logically true that either formulation is valid, the one that
helps students is the only one which should be used in introductory courses.
In other words g should be considered to be derived from the Newton's
gravitational force law (which maybe should really be Hook's force law).
One can then speak of the acceleration due to gravity a_g separately.
Please notice that my argument is not about which is true, but which is
better from the point of view of teaching. The best teaching formulation
can only be decided by experiments, and not by logical arguments.

John M. clement
Houston, TX

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.