From:	Christopher Bellovary <bellovar@***.WISC.EDU>
Subject:	Re: Gravity
Date:	Thu, 24 Jun 1993 05:01:32 CDT

] gravity is a force of acceleration....
] acceleration imparts a change in velocity to a unit mass...
>
> Not according to Einstein.
>
> luke

OK Luke, I don't want to be argueing the wrong point. You tell me
WHAT is it you have the problem with?

1) Gravity is a force of acceleration - known to be true.

2) Acceleration imparts a change of velocity to a unit mass - also known
to be true. The basic formula (sans friction, drag, and all...)

Final Velocity = Initial Velocity + (Acceleration * Time)

3) Inertia is the tendency of a body at rest to remain at rest or of a
body in motion to remain in motion (in a straight line) unless
affected by an external force.

Gravity is an external force:

Force = Mass * Acceleration
Gravitational Force = Mass * Acceleration of gravity (under constant g)

From these, we can see that the motion of a body is affected by
the acceleration of gravity. Inertia is dependent on mass, velocity, and
external; forces. Now I have proven here that:

1) Gravity affects velocity, unless countered by an equal and opposite
force of acceleration.

2) Gravity is a force.

Mind telling me again how inertia is independent of gravity?
I feel like I am back teaching the 210 students what a mass balance is...

It _is_ possible that someone is getting confused between the
concepts of inertia and moments of inertia. Moments of inertia deal will
inertial rotations, and henceforth _are_ independent of gravity. However,
we are dealing with the inertial forces of armed and unarmed combat, which
are not.

Example: You throw a person. If inertia was independent of gravity,
he would continue in that staight line until he hit something. However, it is
not. He hits the ground, gaining in velocity as he falls due to the force of
gravity. His force at which he lands is no longer dependent entirely on the
amount of force you put into it, but the increase in velocity due to gravity
as well. (which is why throwing him might not kill him, but throwing him off
a cliff probably will.)

Are we clear now? By the way, even Einstein followed these rules.
Unless you are talking about someone other than Albert?


=- CrossFire -