Re: Periodic motion vs. oscillation

[Jack Uretsky <jlu@HEP.ANL.GOV>]

Hi all-
        If teachers debate the usage of a word with no resort to a
dictionary, is it any wonder that students are unfamiliar with that
particular tool?
______________________________________________________________________
Main Entry:os£cil£late Pronunciation:**-s*-*l*t Function:intransitive verb
Inflected Form:-lat£ed ; -lat£ing Etymology:Latin oscillatus, past
participle of oscillare to swing, from oscillum swing Date:1726

1 a : to swing backward and forward like a pendulum b : to move or travel
back and forth between two points 2 : to vary between opposing beliefs,
feelings, or theories 3 : to vary above and below a mean value synonyms
see SWING
  –os£cil£la£to£ry \**-s*-l*-*t*r-*\  adjective
______________________________________________________________
MW Collegiate 2004

On Tue, 22 Jun 2004, Bernard Cleyet wrote: 1 a : to swing backward and
forward like a pendulum b : to move or travel back and forth between two
points 2 : to vary between opposing beliefs, feelings, or theories> How
does this apply to electronic oscillators? 3 : to vary above and below a
mean value> synonyms see SWING> The std. method to release a pendulum w/o
"a push" is by burning a fine
  –os£cil£la£to£ry \**-s*-l*-*t*r-*\  adjective> thread.
> And in an LCR osc. the "natural" frequency is a function of the
> damping;  is this true for a pendulum?
>
> bc
>
> bc
>
> Michael Edmiston wrote:
>
> > Robert Cohen's and Hugh Haskell's usage appears the same as mine.  Hugh
> > also raises the valid point that the period of oscillation might not be
> > exactly constant.  My simple pendulum example is one for which the
> > period is not constant unless the amplitude is constant.
> >
> > When the restoring force is linearly dependent on the displacement, we
> > have simple harmonic motion and the period is not amplitude dependent.
> > Therefore, if the oscillation is damped, the period does not change as
> > the oscillation amplitude decays.  On the other hand, if the restoring
> > force is not linear, such as in the simple pendulum, then the period is
> > amplitude dependent.  In the case of a damped simple pendulum, as the
> > ocillation amplitude decays, the period become shorter.  A
> > simple-pendulum clock will speed up as it unwinds if the escapement does
> > not maintain a constant amplitude as the spring unwinds.
> >
> > In my usage I do not restrict that "oscillation" keep constant period.
> > I only restrict that osciallation requires a restoring force that brings
> > the object back through an equilibrium position at which point the
> > restoring force is zero.  Other forces (such as friction) do not have to
> > be zero at the equilibrium position.
> >
> > Michael D. Edmiston, Ph.D.
> > Professor of Physics and Chemistry
> > Bluffton College
> > Bluffton, OH 45817
> > (419)-358-3270
> > edmiston@bluffton.edu

--
"Trust me.  I have a lot of experience at this."
                General Custer's unremembered message to his men,
                just before leading them into the Little Big Horn Valley