ISPP REMINDER

OCTOBER, 2006

OUR NEXT MEETING...

...is at Oak Park-River Forest High School

Wednesday

October 18, 2006

6:30-8:30 PM

Click here for a map, directions and parking information.
Kevin McCarron, 708.434.3195

FUTURE ISPP MEETINGS…

Dec 5	Tuesday	DePaul University - John Milton and Gerry Lietz
Jan 17	Wednesday	Elmhurst College - Earl Swallow
Feb 15	Thursday	Northeastern Illinois University - Paul Dolan and Joe Hermanek
March 7	Wednesday	Chicago State University - Mel Sabella
April 3	Tuesday	Lake Forest College - Mike Kash and bailey Donnally
May 7	Monday	Northwestern University - Art Schmidt
June 5 or 12	Tuesday	either Museum of Science and Industry or Columbia College

<>
OTHER MEETINGS...

Chicago Section AAPT Meeting – Saturday November 11 – New Trier High School – Nick Drozdoff and Tom Senior
AAPT National Meeting – January 5 through 10, 2007, Seattle, WA

AT OUR LAST MEETING . . .

At New Trier High School West, Tom Senior held up a metal ring and a chain about 40 cm long, released the ring so that it rotated as it fell, and… see the picture … the ring is tied to the chain! Tom’s handout said the knot is called a lark’s head or cow hitch. Our giveaway was a PVC version (of course) and a string loop. Tom also had a large glass mug with a very long string of beads in it. When he let a small length of the string begin to fall outside the mug, it continued to fall until the mug was empty – something like a siphon, he suggested. Tom said he got the beads from Educational Innovations (Polymer Bead Demonstration, $19.95). Kevin McCarron (Oak Park-River Forest High School) was asked to have some telescopes out for us when we come to his for the October meeting. Two new teachers were introduced, then our other New Trier hosts each made a presentation.
Bob Pasquesi showed us a setup he uses to illustrate the use of significant figures, using a galvanometer and series resistors as a voltmeter connected across a power supply. Very small resistance changes did result in an observable change in the large meter needle position. Jan Leonhardt gave us information about a summer workshop she attended sponsored by the Convergence Education Foundation, on the physics of cell phones and wireless communication. Jan will try to offer a workshop on some of this material at the Chicago AAPT section meeting.
Nick Drozdoff dipped his trumpet in a dish of soapy water and then blew a loud note.  We saw that there was little expansion of the bubble, illustrating the fact that there is not much net air movement associated with a sound wave, as compared to the speed of the disturbance. Nick then let us hear the change in pitch (a drop?) associated with the player’s insertion of a hand into the bell. Then he played and illustrated from a CD the phenomenon of “multi-phonics” that produces audible beats. John Miller gives his students graphs of position or velocity vs. time on 81/2 x 11 sheets for different kinds of motion (constant velocity, acceleration, etc.) and asks them to hold them up and identify the graphs that correspond to theirs (e.e., uniformly changing velocity with constant acceleration). This serves as a good review of basic kinematics. We were able to take our own copies of John’s graphs.

John Milton (De Paul University) gave us a copy of a poem by Rita Dove, “The First Book,” and suggested we see in it what we do as physics teachers. He showed us two things from Educational Innovations, “Animags” and a Diamagnetic Levitation Demo. Animags are frogs in two parts held together by magnets, so they can look like they are passing through a surface. ($4.95 for a set of three.) In the levitation demo a small neodymium magnet “floats”; it is attracted upward by a magnetic field but is held in equilibrium by diamagnetic repulsion between two between two graphite blocks. ($59.00) It comes background material and some suggested uses.

Bill Shanks (Joliet Central High School, retired) found a “Pumpkin Light” at Walgreen’s for $4.99. It has three LEDs (RGB) and cycles in different sequences, so one can see the results of different kinds of color mixing.  Bill also showed us a magnetic base LED Flexilight and a multipurpose tool (see photo) that he got from Cabela’s.com and is also available at Menards.

Dan Cahill (Grayslake Central High School) brought out a table fan and a piece of string with a frayed knot at one end. He suggested that the space in the moving air from the fan could be called a “fan field” by way of analogy to an electric field. The string and knot act something like “test particle” in an electric field; there is more deflection where the air flow “field” is stronger. It was suggested that two fans could act like the field due to two charge distributions. Jan Dudzik said she has use a horizontal paper arrow pivoted on a pin stuck in a piece of foam as as a field probe. Martha Lietz told us she has used oppositely charged pieces of tape on a meter stick brought near a Van de Graaf generator.

Jan Dudzik (Naperville Central High School) passed out fliers on the “Conquer the Hill Competition” her students will enter. It is a dueling cart event sponsored by Lucent Technologies. Harry Kyriazes (Niles North High School) had some solid plastic disks that he uses to illustrate refdraction and reflection of light from small lasers.

	Scott Beutlich (Crystal Lake South High School) showed us some optics teaching devices: an old parabolic lighter he got from Bruce Illingworth, an Euler’s Spinning Disk from Edmund Scientific, and eight laser levels he got at Menards. Beams from the laser levels could be seen passing through a water tank with a submerged air lens, and were visible in air using spray smoke (“Fog in a Can”) from Arbor Scientific.
	Paul Dolan (Northeastern Illinois University) bought some personal massagers (Walgreens) and asked us to speculate on why they rotate when placed on a level surface. He puts some waffle mix in a non-flat metal mixing bowl, adds water to the mix and stirs. It takes a while but he is able to get the bowl to rotate – the rotating mix, he said, exerts a torque on the bowl. He didn't bring waffle mix, so he tried water - there was a little rotation.

Dave Lowry (Hillcrest High School) showed some things he uses to help teach about rotation. The first was a variable color LED gyro top from XTREMEGEEK.COM. It contains a battery powered gyroscope that keeps it spinning for several hours. He then showed us an excerpt from a History Channel Modern Marvels program on the wheel. Dave also had an expanding sphere whose rotation rate changes as its diameter changes, to illustrate conservation of angular momentum. We left with a variety of giveaways and handouts, and even some leftover cookies. Thanks tour New Trier hosts! Submitted by John Milton.

For any information regarding ISPP contact Gerry Lietz at DePaul University, Physics Department, 2219 N. Kenmore Chi. IL 60614 phone: 773-325-7333 e-mail glietz@depaul.edu. ISPP home page:  http://condor.depaul.edu/~glietz/ispp/ispp.html