High School Physics Smile [11-25-97]
Notes Prepared by Alex Junievicz
Bill Blunk [Joliet Central HS]
A Simple demo of wave beats using pop bottles. [based upon a recent article in the Physics Teacher.
Having the bottles filled more than half and blowing over the tops produces a tone, the frequency of which can be changed by adding or subtracting some of the H2O in the bottles. One possible
can excite the two bottles, but it is much more practical for two people each with one bottle.
Comments were made that an echo at a time of about 40milliseconds [ms] later is acceptable, whereas echoes at time delays of 200 ms are aesthetically detrimental. A live room with a short echo is appreciated while echoes over time intervals grea ter than 100 ms cause the sounds to seem dissonant to the listener. Also piano tuners use harmonic resonance to tune a piano in the higher octaves, and they can resolve differences of 1/5 cps using beats..
Lee Slick [Morgan Park HS]
He had a project using a coat hanger where one balanced a dime on the end and swung the hanger around. The coin would stay on the coat hanger end.
Debbie Lojkutz [Joliet West HS]
She had us go into the hallway to pull a cart constructed with 2 skate boards as the wheels. The idea is to change the pulling force and then to change the mass (2 people). This is set-up to show relationships between force, mass, and acceleration, a nd not a quantitative study of Newton’s Second Law.
Table Force # masses Time Distance Acceleration
Part 16 Nt 1 11.0 6 m .10. m/sec2
I 32 Nt 1 7.3 6 m .23 m/sec2
Part 40 Nt 1 5.0 6 m .48 m/sec2
II 40 Nt 2 9.0 6 m .15 m/sec2
We discussed the effect of changing the variables, and that we needed to only change one at a time. Otherwise our conclusions and predictions may be flawed.
Arlyn van Ek [Illiana Christian HS]
Did a variation on the boat crossing the river using a sheet of moving paper and a powered car. The setup is based on a problem in the standard textbook by Merrill, concerning a "paper river". One must add velocities as vectors to d etermine the direction of travel of the powered car on the moving river. If the car is aimed straight across, it is deflected downstream by a certain angle by the motion of the paper. Interestingly enough, to make the car go straight across, it must ha ve a net upstream motion relative to the paper, but it is not correct to aim it upstream by the same angle as it went downstream when going straight across in the rest frame of the paper.
Fred Schaal [Lane Tech HS]
He gave a scheme for remember the conventions of "True" and "False" statements.
He went through and was curious of all the combinations of the logic and the possibilities especially, where they were in essence the same result.
|Editors Note |
| early computers used diodes as logic elements |
| and transistors and inverters. |
| A good practical reference is the handbook for |
| IC's especially the 7400 series which are |
| logic elements AJ |
Betty Roombos [Gordon Tech HS]
Inquired who was uses Computer Technology in the classroom, and how it is used.
John Bozovsky [Bowen HS]
He commented on the 3 years of Science interpreted by CPS
Biology (first year)
Earth or Environmental Science
Chem or Physics (operative -OR-)
These comments were made:
1. Earth Science doesn’t necessarily make you more technologically knowledgeable
4. The plan makes it required to take Chemistry or Physics, and difficult to take both.