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Re: Apparent weight



First, I apologize to A. R. Marlow and the list for my last few posts. They
have been too cynical. I would like to be enlightened to GR, so will discuss
my conclusions and ask for feedback.

First, I'll assume that whatever Newtonian mechanics tells me concerning the
motion of a mass, GR will tell me the same thing at least within the scope
where Newtonian mechanics gives good results.

If I drop a ball, then I see it is accelerating with respect to my frame of
reference. To analyze this using Newtonian mechanics, I would say there is a
force acting down on the mass and describe this force as the weight. I'd
write (I'll assign up as my positive direction):

Fnet = ma
-W = ma
-mg = ma
a = -g

I would therefore conclude that the weight being the only force, the
acceleration would be g downward.

Now, Marlow states that W is a fictitious force, so I don't want to include it
on the Fnet side of the equation (where the real forces belong). Therefore, I
move it to the right side (as a frame of reference acceleration) and write:

Fnet = m(a+g)
0 = m(a+g)
a = -g

This says that when no force is acting on the mass, then it will have an
acceleration of g with respect to my frame of reference, the same result as
Newtonian mechanics.

Now, I stand on the floor and feel a force acting up on me. In Newtonian
mechanics I write:

N - W = ma
N - W = 0
N = W
N = mg

In GR I write:

N = m(a+g)
a = 0
N = mg

Now, I stand in an elevator that is accelerating. In Newtonian mechanics I
write:

N - W = ma
N = m(a+g)

In GR, N is the only real force and write:

N = m(a+g) directly.

How am I doing so far? Got to go to class.

Bob Carlson