Date: Sun, 6 Jul 2003 09:28:50 -0400

Author: Chuck Britton

Subject: Re: Jerk

Post:

As a died-in-the-wool intuitionist (i.e. analytically impaired),
often throw an anthropomorphic viewpoint into these problems.

Tossing the ball straight up seems to me to be about a simple a
problem as it can get. Now let's add the highly trained 'Physics Ant'
to the demo.

If your students aren't comfortable with reciting the mantra 'The
ant, while in free-fall is weightless' then you can forget about this
explanation.

The ant is weightless for the entire upward journey BUT returns to
normal weight at the instant that the brakes are applied.

THAT delta a is the jerk. The ant feels it so it is real!

weird!!

(don't embarrass your colleagues TOO much by asking questions about jerk ;-)


OK, ya'll, at 12:53 AM -0500 7/6/03, Patricia Sievert wrote:
>What about the case of a ball tossed straight up. It is
>experiencing a constant acceleration (g, or 9.81 m/s/s downwards).
> At the top of its flight, velocity is zero, but acceleration is
>still 9.81 m/s/s downwards. If at that precise moment, it is
>"caught", there would be no change in velocity, but there would be a
>change in acceleration, or a jerk.
>Pati

--
.-. .-. .-. .-. .-. .-. .-. .-. .-. .-
\ / \ / \ 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) 416-2762 Albert Einstein, 1936
From KBouff@aol.com Mon Jul 7 09:01:20 2003
From: KBouff@aol.com
Message-ID:
Date: Mon, 7 Jul 2003 09:01:21 EDT
Subject: Re: Seeking New Labs
To: tap-l@listproc.appstate.edu
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
X-Mailer: AOL 5.0 for Mac sub 39
X-MailScanner-Information: Please contact the Helpdesk @ 6266 for more information
X-MailScanner: Found to be clean
X-MailScanner-SpamCheck: not spam, SpamAssassin (score=0.7, required 7,
NO_REAL_NAME 0.73)
Reply-To: tap-l@listproc.appstate.edu
Sender: owner-tap-l@listproc.appstate.edu
X-Listprocessor-Version: 8.2.10/991025/16:55 -- ListProc(tm) by CREN

A few years ago I wrote a workshop for AAPT on Teaching about Physics and the
Human body. We concentrated on optics and thermodynamics in this (which was
intended to be the first volume). One activity which was very popular was
dissection of cows' eyes. Students are fascinated by the lens and its composition
(You can actually find its focal length if you use preserved eyes- Nebraska
Scientific). The index of refraction of the vitreous humor is almost the same as
water so when put into water will "disappear." Actually seeing the retina,
blind spot and optic nerve give lots of latitude to talk about the optics of
seeing. We also modeled the effect of convex and concave lenses on the defective
eyes. A number of other labs were adapted from "Try it's" in the book Seeing
the Light. In thermodynamics, after establishing the difference between heat and
temperature we used the body's temperture feed-back system as a model of
bi-metallic strips. We also burned marshmellows and peanuts (heating a given
amount of water in a soft drink can) to find the number of calories.
We were also able to bring in demos and kinesthetic activites on heat
transfer. If you want more info, please contact me.
Karen Bouffard
From KBouff@aol.com Mon Jul 7 09:05:19 2003
From: KBouff@aol.com
Message-ID: <131.2120ef5b.2c3aca17@aol.com>
Date: Mon, 7 Jul 2003 09:05:27 EDT
Subject: Re: Seeking New Labs
To: tap-l@listproc.appstate.edu
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
X-Mailer: AOL 5.0 for Mac sub 39
X-MailScanner-Information: Please contact the Helpdesk @ 6266 for more information
X-MailScanner: Found to be clean
X-MailScanner-SpamCheck: not spam, SpamAssassin (score=0.7, required 7,
NO_REAL_NAME 0.73)
Reply-To: tap-l@listproc.appstate.edu
Sender: owner-tap-l@listproc.appstate.edu
X-Listprocessor-Version: 8.2.10/991025/16:55 -- ListProc(tm) by CREN

One more note on activities, we did measure blood pressure (although didn't
compare leg and arm) and EKG's using the Pasco Data Studio software. These came
out well and books such as Physics and the Human Body give excellent
explanations with respect to the polarization of the cell walls, and diffusion. There
are a number of diffusion or osmosis activities in which students can actually
calculate the height of water which will be supported in a tube when molasses
diffuses into a bag of water.
Karen
From mat3q@virginia.edu Mon Jul 7 12:11:09 2003
Subject: Re: Student Response Systems...
From: Michael Timmins
To: tap-l@listproc.appstate.edu
In-Reply-To: <3F046910.7090302@vt.edu>
References: <3F032BB7.30100@unity.ncsu.edu> <3F046910.7090302@vt.edu>
Content-Type: multipart/mixed; boundary="=-v/R3RcMU3swIYEoCvHiR"
Organization: University of Virginia

Back