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R&M replies from R




double carots are JR single carots are AM, nothing is JR


Let me summarize the conclusions I've made so far (note: this would
not agree entirely with the conclusions Marlow makes from the
discussion).

Everyone agrees that there are effects when you make measurements
in a non-inertial frame of reference. Marlow wishes to only call them
accelerations,

Sorry, but we must be clear at this crucial point: I do not propose
calling ALL effects measured relative to a noninertial frame
"accelerations."
I only propose calling the kinematic quantities normally known as
accelerations "accelerations."


acknowledged, by measurements in the non-inertial frame I meant those that
are due to the acceleration terms or mass time the acceleration term; I
didn't make that clear

... and feel quite
comfortable with multiplying by mass and call the resulting entity a
"kinematical" force. I feel uncomfortable with using the term
"fictitious"
to describe the resulting entity;

So do I, and I would never use the term fictitious of such entities; they
are totally real accelerations, multiplied by totally real masses. They are
only fictitious as forces.

... the reason being the effects are real as
measured in the non-inertial frame of reference and the word "fictitious"

has connotations of unreality.

Agreed.


We are very close to agreeing, (except below)

... I don't think one can make measurements in
the non-inertial frame that can distinguish these terms

If your still talking about the distinctions between measuring forces
and measuring accelerations, I can only refer you to all that has been
previously posted on this.

The measurements I'm referring to are the ones that you can predict from
Newton's laws; namely the postion, velocity and acceleration of objects;
this is all Newton's laws can tell when you solve them; it also provides a
background for understanding what's going on. I think you have above agreed
that the equations I'm solving are formally the same as the 2nd law;
therefore the conclusions are formally the; e.g. the work-energy theorem.
... as their introduction is
precisely so you can use the 2nd law and 3rd law (and hence all
of mechanics) in non-inertial frames and analyze things consistantly and
get
correct answers.

Once again, standard mechanics says that Newton's laws simply do not
apply in noninertial frames and there is no attempt to make them apply in
such frames. You do not get correct answers: for example, you calculate
nonzero work done by "centrifugal force" in the examples discussed
previously, I calculate zero work done by such a "force." Both answers
obviously cannot be correct.

This contradicts the mathematics which is formally equivalent, which is what
the authors I quoted are saying; I'll quote some more in a future post.

...
So, one way to define a force then is operationally, by observing
the objects acceleration. If I stop there then I believe Marlow is
absolutely correct in saying I've reduced dynamics to kinematics. But
there
is nothing wrong with that and "my" physics is perfectly consistent in
doing
that, I get the same answers that Marlow gets to analysizing problems;

Sorry, but you do not get the same answers for important dynamical
quantities, as I have already pointed out in previous posts ( M+m vs.
M alone in Newton's correction to Kepler's 3rd law), and above (nonzero
work vs. zero work).


I've asked Marlow to send me a copy of the relevent posts here, so I can
address the
question.
Joel Rauber
rauberj@mg.sdstate