Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

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

Why?
What is so strange about writing F=mA in component form?
You do it all the time!
I merely point out that there is a "universal" utility in writing it in
components parallel and perpendicular to the velocity vector!

Bob

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

----- Original Message -----
From: Chuck Britton <britton@ODIE.NCSSM.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Saturday, October 23, 1999 6:43 PM
Subject: Re: Newton's 3rd law? was Re: inertial forces (definition)


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.

-. .-. .-. .-. .-. .-. .-. .-. .-.
.-
\ / \ / \ N / \ C / \ S / \ S / \ M / \ / \
/
`-' `-' `-' `-' `-' `-' `-' `-'
`-'
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