[Phys-L] Re: Aristotelian thinking among modern students

[betwys1 at SBCGLOBAL.NET (Brian Whatcott)]

Hmmm....
a line that's concave to one side is convex to the other.
I didn't specify no dissipation.
By all means read drop for dip as altered below.

Brian

At 05:37 PM 10/20/2005, you wrote:
> Nit pick?: You mean crossing the zero line?  Dipping implies a concave line.
> bc, who hopes the debate will recommence.
> p.s. are we to imagine no dissipation?
>
> > if I drive a car up a slope  then engage neutral,
> > the car slows and reverses, back down the slope.
> >   The velocity is graphed by a straight line slope, dropping through
> > zero at the car's high point.
> >   The acceleration on such a graph would be a straight
> >   horizontal line. That is, it is non-zero, when the velocity
> >   goes through zero.
> >
> > Now consider the case when I drive forward, coast to a standstill,
> > and at the moment the speed is zero, I apply the brake.
> > What is the physical significance of the acceleration dropping
> > suddenly to zero?

Brian Whatcott    Altus OK    Eureka!