SMILE notes for High School Physics Meeting of 10-14-97 [prepared by Alex Junievicz]

Jane Shields [Chicago SDA Academy]

She would bread the student up into groups, One would determine the # of Electrons, and the Protons, etc. from the periodic table. The plug-in pegs were put at the appropriate position . She use Helium [He] for a demonstration because it is a simple configuration.

Comments by Porter, Roy, Ann, others?:

1 x 10⁶ nuclear diameters » diameter of atom (very very small), and the electron is not an object but a cloud.

State Board of Education will permit you to borrow and copy the video Powers of Ten by Ames.

The CD ROM Street Atlas USA 4.0 has a digital map of the USA, which can be magnified by factors or two simply by "pointing and clicking". One can print a map of a region from magnitudes 1 to 16.

Roy Coleman [Morgan Park High School[

He discussed some math anomalies. He asked the class to pick a number 1,2,3,4 and most of the

class picked 3. About 80% of people will pick 3 not the first and not the last number

He teased with the old 1 + 2 = 4 i.e.

If you take an and erase the right line you get (good comeback if a student says they only left off a little bit)

7641 Number not same digits, in decreasing order

1467 same digits, but in increasing order

----------- subtract

6174 > This number, sometimes called Voodoo number, will always occur, although it may

Porter-

Take a 3 digit number with distinct digits, reverse the digits, and subtract

the smaller from the larger. Then take the new number, and reverse its digits,

and add the two together. The answer is always 1089.

htu 865

100h + 10/t + u - 568 reverse digits

100u + 10/t + h ---------

__________________ 297

+ 792 reverse digits

99h - 99u = 99(h-u) ---------

Cast out 9's 1089

Carole Zimmerman [Lane Technical High School]

She announced that she and others have developed an interactive work sheet based upon questions asked during a field trip to the Museum of Science and Industry, which was developed for students who did not participate in their Great America fiel d trip. It will be available on diskette for $2.00 at our next SMILE meeting.

Bill Blunk [Joliet Central High School]

He described a Force Stick, available from the Science Kit Catalogue as item # 45444 for $13.75. The device reads force, and it has a sliding sleeve that records the "maximum force". It is calibrated for acceleration by attach ing a standard mass to it. It is rather more portable and user-friendly than the usual "accelerometer", and much more durable. He tested it by dropping it with a "suction cup bottom" attached, and looking for the maximum displacement , and also with a "super ball bottom". It seemed that in the second case the maximum force [acceleration] was about twice as large as in the first case. The device also properly recorded centripetal acceleration as inward bound.

Fred Schaal [Lane Technical High School]

He decried the lack of good billiard tables, and described the crucial "break shot" in billiards [3 balls; table with no pockets]. The "three cushion " shot requires a decent table, in that one must hit a cushion three times before hitting the target, without hitting the "other ball". In an ideal collision with a non-spinning ball, the angle of incidence is equal the angle of reflection. With the right sort of spin this is still true, and the angular velocity reverses d irection. This is related to bouncing super balls off the bottom of tables.

Larry Alofs- [on leave from Kenwood High School]

He reported on complications of his eye problems

Review - It seems that heredity was important in being susceptible to what seemed at first a detached retina .Laser and cold compresses(?) were used to re-attach it, but there still seemed to be stress on the cornea. To get pressure in the atta chment region, a band was placed around the eye to get the vitreous humor to push back the retina. Lately he noticed a distortion in the center area of the eye. Seems that some renegade muscular fiber was growing and causing the problem. They replaced the vitreous humor with Silicone Oil and removed the lens to be able to get and clear the growth. For a period the Vitreous Humor has been replaced by a salt water solution. Care must be used because the solution between the iris (where the lens was re moved) and the cornea cannot be allowed to mix with the solution in the eye. Without the natural lens he found that a 7 diopter lens in front would allow some focus. He must keep his head straight forward to down. .Never look up. He looked at an old Ph ysics Book to learn that a diopter is the inverse of the focal length [given in meters]. [Note: diopter units are used by ophthalmologists because lenses in diopters can be added, whereas we poor physics teachers have to add inverse focal lengths; etc. < /P>

1/f = 1/f₁ + 1/f₂ versus d = d₁ + d₂

Even negative lenses can then be tested, and also the vari-opter uses a set of lenses that are added to get the desired focal length.]

Alex Junievicz [CPS substitute teacher]

Brought in an Al tube cannibalized from a TV antenna.. Although it has several holes from the previous life a cow Magnet slid slower than the PCV pipe, but still quite fast. .He acquired another Cu pipe without a slit and the magnets went slower in th e Cu pipe with a slit down the tube which was shorter. During the ISPP meeting the tubes were "massed". The slit tube was 649G and the complete tube was 551G. Both

tubes were purchased in the Plumbing Department. Farm and Fleet in Kenosha was the source of the Magnets and the one that now has a slit and Home Depot [Route 59 and 75^th Street] was the source of the one still complete. I assumed that both were for plumbing and have the same thickness. Still what is

surprising is that the slit seems to make no difference.