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

[Chuck Britton <britton@ODIE.NCSSM.EDU>]

At 6:40 PM -0400 10/23/99, Bob Sciamanda wrote:
> One can always resolve these vectors in two perpendicular directions,
> chosen parallel and perpendicular to the present velocity vector:
>
> F_t = m dv/dt , and
> F_c = mv^2/r .  , where
>
> F_t is the component of the net force tangential to the present velocity,
> and
> F_c is the component of the net force perpendicular to the velocity and
> directed toward the center of curvature (r);  v is the instantaneous
> speed.
>
> This can always be done and is very useful.  There is no exception to this
> method of decomposition of F=mA.
>
> Bob

I *THINK* that the pedagogical point that some are trying to make
(and which I agree with) is that it is better to refer to v^2/r as
the centripetal acceleration that goes on the RHS of N2 rather than
as a force component that does on the LHS thereof.

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Chuck Britton                                   Education is what is left when
britton@odie.ncssm.edu                          you have forgotten everything
North Carolina School of Science & Math         you learned in school.
(919) 286-3366  x224                            Albert Einstein,        1936