Re: Arons and Dry Ice

[Larry Woolf <larry.woolf@GAT.COM>]

You can have comparable Galilean experience by rolling a bowling ball and
watching it sail away.  Or by pushing a racing bike with high pressure
narrow tires carrying a light rider.  I suspect that the ball and the bike
will travel longer than the length of the glass that is used in the dry ice
experiment.

More useful is to determine how the distance traveled as well as how the
speed changes vary with different surfaces.  By making plots, one can see
that as roughness/friction decreases, the motion more closely behaves in a
frictionless manner. Students need varied experiences to provide them with
the ability to extrapolate their real world experiences to the idealized
Galilean world.

Larry Woolf;General Atomics;San Diego CA
92121;Ph:858-526-8575;FAX:858-526-8568; www.ga.com;www.sci-ed-ga.org

-----Original Message-----
From: Bernard Cleyet
Sent: Wednesday, October 09, 2002 1:19 PM

Huhhh?

I thought the point was our usual experience is mediated by high friction
that
confirms Aristotelian Physics.  A block of gas supported ice reduces the
friction, so
one may have a Galilean experience.

bc puzzled and
who assumes this post is the position of Richard et al.

Larry Woolf wrote:

> As much as I appreciate Richard Hake's posting, I take issue with this
one.
> The Phys-L posts have revolved around the kinesthetic experiences of
pushing
> bowling balls, cars, bikes, etc.  You can't much more kinesthetic than
that.
> It also seems to me that real-life experiences that vary slightly every
day
> and also occur everyday provide powerful contexts for learning, for
> continual reinforcement of learning, and for the transfer of that
learning.
> http://www.nap.edu/html/howpeople1/ch3.html (see the "Context" section)
> We often use cars, bikes, and bowling balls, whereas we rarely push large
> blocks of dry ice on glass.

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.