Re: Impulse

[cliff parker <cparker@CHARTER.NET>]

Good point.  Thanks for the correction.


> The FIRST padded dash boards were covered with foam rubber. Then the
> accident watchers noted that there was an INCREASE in concussions.
>
> Dashboards were quickly converted to CRUSHABLE padding that prevents
> the rebound. Having the head bounce BACK after the initial impact was
> a BAD thing!
>
> The crushable dashboard applies the same force for LESS time than the
> bouncy dashboard.
>
>
>
> At  8:17 PM -0600  on  10/30/01,  cliff parker   wrote
> >  >
> > >  > Impulse is a push for a while.  I can stop a speeding Mac truck two
> > ways.
> > >  > Push it hard for a little while or push it easy for a long while.
> > >
> > >  What about using the term impulse to describe a large but
exceptionally
> > brief
> > >  force?  Is this a well defined concept?
> > >
> > >  Justin Parke
> >
> > Sure it is.  Unfortunately automobiles are often stopped by large brief
> > forces administered by things like large trees.  Dashboards used to be
bare
> > metal.  They typically exerted forces over a shorter time period and
> > therefore require a larger force to change the momentum of the occupant.
> > Since we now cover dashes with foam rubber the time that dashboards are
in
> > contact applying forces to the occupant has increased this allows a
smaller
> > force to change the momentum of the occupant.
> >
> > Cliff Parker
> --
>
>   .-.     .-.     .-.     .-.     .-.     .-.     .-.     .-.     .-.
.-
>      \   /   \   /   \ N /   \ C /   \ S /   \ S /   \ M /   \   /   \   /
>       `-'     `-'     `-'     `-'     `-'     `-'     `-'     `-'     `-'
> Chuck Britton                                   Education is what is left
when
> britton@ncssm.edu                               you have forgotten
everything
> North Carolina School of Science & Math         you learned in school.
> (919) 286-3366  x224                            Albert Einstein,
1936