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*From*: Don Metz <DMETZ@collegiate.uwinnipeg.ca>*Date*: Mon, 01 Apr 1996 08:30:00 -0500 (CDT)

And once again I have to ask: Where is the problem? Maybe I'm

used to my terminology too much, but to me 'g' is an

acceleration: When I let a body fall (air removed) it IS

accelerated with a~9.8 m/s^2. This value *describes* what happens

(and in what way), it doesn't give a reason why.

g is the gravitational field constant. It is a unit force, the force

on 1 kg of mass near the surface of the earth. It is analogous to

the electric field constant (E = F/q) and we can describe the

magnetic field in a similar manner (B = F/Il). The common

description of g as the acceleration due to gravity comes out of an

analysis of free fall where for an object falling freely

Fnet = ma and Fnet = Fapplied + Ffriction

For a sufficiently dense object falling a short distance near the

surface of the earth Fapplied = mg and Ffriction = 0.

then Fnet = ma and Fnet = Fg + 0

i.e. Fnet = mg

So ma = mg and a = g.

That is, the acceleration of a freely falling body equals the

gravitational field constant. This treatment I believe is important,

g is the gravitational field constant, the accleration of a freely

falling body equals g, g is NOT defined as acceleration. Defining

g, E, and B as field constants enables us to make important

connections between gravitational, electric, and magnetic phenomena

and permits to begin to examine elementary field theory.

my $0.02 :)

Don Metz Phone: 204-786-9241

Collegiate Division Fax: 204-775-1942

University of Winnipeg email: dmetz@collegiate.uwinnipeg.ca

515 Portage Ave.

Winnipeg, MB

R3B 2E9 Canada

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