Re: Newton's 3rd law? was Re: inertial forces (definition)

[Bob Sciamanda <trebor@VELOCITY.NET>]

Hi again, Jack
Forgive me for dipping twice, but, inspired by recent political events to
marshall every legalism in combating frivolous prosecution, I offer this
more politically relevant reply.  See below:    :)  :)  :)

----- Original Message -----
From: JACK L. URETSKY (C)1998; HEP DIVISION, ARGONNE NATIONAL LAB ARGONNE,
IL 60439 <JLU@HEP.ANL.GOV>
To: <PHYS-L@lists.nau.edu>
Sent: Saturday, October 23, 1999 6:59 PM
Subject: Re: Newton's 3rd law? was Re: inertial forces (definition)


> Dear Bob-
>         Not so fast, my friend:
> You write
> *************************************************
> The centripetal component of the acceleration is v^2/r .
> The centripetal component of the net force is mv^2/r .
> ***************************
>         Au contraire.  The quantity mv^2/r is the mass times the
acceleration
> which is numerically equal to the applied force (contact or one of the
forces
> that act at a distance).
> . . .
>                                 Regards,
>                                         Jack

It depends on what the meaning of "is" is!
In my above statement "is" symbolizes a numerical equality.

This should lighten everyone up (maybe not!) .       :-)

Bob

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor

"In the hard sciences we mostly talk about models rather than laws.  And
if you talk to the people who are working on foundations of mathematics,
they also talk about models.  It's certainly true of physics and astronomy
in particular that a law is just a model that we've got used to.   . . . I
have enormous respect for Stephen Hawking, but I sometimes think he
doesn't know the difference between a model and the real thing.  That's an
occupational disease of theoretical physicists."

Freeman Dyson in ("A Glorious Accident", W. Kayzer ed.)