Bill Colson [Morgan Park HS]
How is it possible to suck spaghetti into your mouth?
The audience experienced the phenomenon with samples of foul-tasting pseudo-spaghetti, and drew these conclusions:
There is a pressure difference and the spaghetti will enter the mouth because the friction of the spaghetti will allow the spaghetti to be pushed by the pressure difference toward the lower pressure inside region.
See Readers Digest for January 1999.
Cynthia D'Souza [DeLaSalle High School]
She worked on a NSF project during summer
Pre-Lab
After Lab
Loop
She had several stations that had a ramp of at least 30 cm high and had at least 20cm of table on which the ball rolled. A photo-gate that was attached to a computer that was programmed to measure the time the ball obscured that photo-gate and calculate with the known diameter of the ball and respond with the velocity of the ball just before it left the table.
One problem was that the steel ball provided had a tendency of bouncing as it rolled on the table. Another problem was noted by the receptor of the ball that had some height. Still another problem was where to measure to the cup which the rules indicated the ball should not touch the sides. One group substituted the given steel ball with one of the Happy-Sad type balls.
Knowing the velocity of the ball leaving the table, it was simple to compute the time that the ball took to fall the distance from the table down to the top of the can and then knowing the time, calculate the distance laterally that the ball would travel till it hit the cup
More about this in the future.
Bill Blunk [Joliet Central HS]
Another modeling presentation<
Using flat magnets (either from Radio Shack, or American Scientific)
Using red tape put a+ on one side and a - on the other, then static
charges can be modeled. He also pointed out the no charge was actually
both + and - 's
Ann Brandon [Joliet West HS]
She showed by using a diffraction grating finding the wave length. She passed out a worksheet that used [1] Laser Printer and [2] a diffraction grating with known parameters. She used the grating at 2 meters, measured the diffracted image, and then calculated the wavelength
Also she brought in several mailings
Metrologic Company Catalogue has a section describing various laser
projects
National Teachers Enhancement Network Course CatalogSee their webpage: http://www.nsta.org
BTC.montana.edu/nten
Kim Obbing, kobbing@nibtaba,edy
George Tythill, tuthill@physics.montana.edu
NTSA Fax on demand 1-888-400-6782
Alex Junievicz [CPS Substitute]
He showed the only good pot-hole. The problem is with a wheel to try to get out of the pothole Speed is the first thought, but actually there is less movement as the speed is increased---the only way is rock--getting momentum.
He also showed a give-away that had a front surfaced mirror and behind is a regular mirror....Every second reflection can be noticed by the brightness-color of the image. First showing the sandwich covered by a box, and removing the box and still seeing the progression of the image still being the same. Another sterling way is showing it by holding it in front of the body.
Another comment was that a math teacher allegedly got severe eye damage at Juarez HS because a student pointed a laser at her eye.
Bill Shanks [Joliet Central HS, retired]
He bought a Metronome and found a use for it. One plan for use was to judge the speed of a car passed, or passing. First take a starting point and getting a timing of each up to a fixed point. [2 sec for the faster car; 3 sec for the slower car] The ratio is 3/2, and if the slower car is traveling at 60 MPH thus the faster car was traveling at 90 MPH
NEXT MEETING is in 2 weeks--- The regional bridge contest, at the HUB [Hermann Union Building]. See the website: http://bridgecontest.phys.iit.edu/