VIRGINIA
INSTRUCTORS of
PHYSICS



FALL 1994 Vol 9, No 1

HURRY HURRY
The Next VIP Meeting is Saturday, Oct 8, 9:00 to 3:30 At the University of Virginia.

This meeting promises to be one of the best ever. Get to know your peers. Share ideas.
AGENDA

 9:00 -  9:30 Hello's ...Coffee and donuts provided by UVa
 9:30	- 10:00 VIP Business
10:00 - 10:15 What VaPEN will look like in the future (...next year?)
10:15 - 12:00 Image Processing for Teaching: Beyond Digital Video
              H.I.P. physics (CD ROM motion analysis and more)
              by Dr. Bob Kolvoord (author, editor and more of
              *H.I.P. Physics*.) 
              See extended description below
12:00 -  1:30 Lunch (You will have to provide your own lunch ...restaurants are near 
by.)
 1:00 -  1:30 Collect freebies: catalogs, demo write-ups, lab tips and more, (over 
laps
              lunch).
 1:30 -  3:30 PASCO Scientific presentation: "Computer Usage in the Lab"
              See extended description below



At out last fall meeting everyone left with something. We are doing it again! ...And the meeting is free!
Many physics teachers are starting to explore the use of digital video as a part of their instruction. The "Image Processing for Teaching" (IPT) project provides a powerful medium to excite all students about physics. Image processing provides a powerful set of tools to do both qualitative and quantitative analysis with images from a variety of sources, including digital video. The opportunities for exploration and discovery are vast, opening up the world of physics to students from a variety of backgrounds and abilities. Mathematics is present at every stage and can be used to help students integrate mathematics and physics into situations outside the traditional classroom.
Classroom applications of image processing have proved to be both an effective and efficient way to augment physics instruction. From simple applications using captured digital video in place of the standard laser disk to studentUs own projects, image processing opens up a world of exploration and discovery for all students. Even students who have not fared well in the traditional physics curriculum can learn using digital images.
In this talk, Dr. Kolvoord will show a variety of images and curricular applications from both digital video and other sources. Feedback from the more than 1200 teachers already doing image processing in their schools show that image processing is an effective and fun way to study the application of physics to "real world" applications, as represented by digital imagery. We will also discuss the ongoing development of curricular materials at the University of Arizona and preview some new materials.
More on the morning presentation... Dr. Koolvard's presentation will feature H.I.P. Physics. H ANDS-ON I MAGE P ROCESSING PHYSICS is H.I.P. Physics. The system uses free N.I.H. image processing software on a Macintosh computer to analyze and image or series of images, i.e. video. Imagine video taping an experiment or activity like a shuttle launch, sending the video signal to the computer, and then analyze the motion for position, velocity and acceleration versus time in a graphical format at the click of a mouse. Dr. Bob Kolvoord is flying in from University of Arizona to make this presentation. Dr. Kolvoord is one of the authors of the analysis macros and applications for the NIH software...And the meeting is free!
Steve Miller is representing PASCO. Steve will be presenting on computer interfacing and what can be done with PASCO equipment. This presentation has been in the making for over a year and a half. ...And the meeting is free!
What really makes this meeting go are people like you. Bring 75 copies of something you do (demo, lab, lecture or whatever) to share. This has always been a great part of our meetings. But you don;t have to bring something to come to the meeting. Did we mention that the meeting is free?

Class Room Activity



by Tony Wayne
First, thanks to Tom O'Neil for the idea. Go to the video store and buy a Road Runner and Wyle E. Coyote video. After covering Newton's laws and conversation of energy laws show the cartoons. Ask the students what laws are violated during each cartoon. After a discusion, give the students the assignment to write a set of cartoon physics laws.
Below are a set of cartoon laws that came across the PHYS-L list system on the internet. Unfortunately the author's name was lost though all the forwarding. Enjoy.
Cartoon Law I
Any body suspended in space will remain in space until made aware of its situation.
EXAMPLE : Daffy Duck steps off a cliff, expecting further pastureland. He loiters in midair, soliloquizing flippantly, until he chances to look down. At this point, the familiar principle of 32 feet per second per second takes over.

Cartoon Law II
Any body in motion will tend to remain in motion until solid matter intervenes suddenly.
EXAMPLE : Whether shot from a cannon or in hot pursuit on foot, cartoon characters are so absolute in their momentum that only a telephone pole or an outsize boulder retards their forward motion absolutely. Sir Isaac Newton called this sudden termination of motion the stooge's surcease.

Cartoon Law III
Any body passing through solid matter will leave a perforation conforming to its perimeter.
EXAMPLE : Also called the silhouette of passage, this phenomenon is the speciality of victims of directed-pressure explosions and of reckless cowards who are so eager to escape that they exit directly through the wall of a house, leaving a cookie-cutout-perfect hole. The threat of skunks or matrimony often catalyzes this reaction.

Cartoon Law IV
The time required for an object to fall twenty stories is greater than or equal to the time it takes for whoever knocked it off the ledge to spiral down twenty flights to attempt to capture it unbroken.
NOTE : Such an object is inevitably priceless, the attempt to capture it inevitably unsuccessful.

Cartoon Law V
All principles of gravity are negated by fear.
NOTE :Psychic forces are sufficient in most bodies for a shock to propel them directly away from the earth's surface. A spooky noise or an adversary's signature sound will induce motion upward, usually to the cradle of a chandelier, a treetop, or the crest of a flagpole. The feet of a character who is running or the wheels of a speeding auto need never touch the ground, especially when in flight.

Cartoon Law VI
As speed increases, objects can be in several places at once.
NOTE : This is particularly true of tooth-and-claw fights, in which a character's head may be glimpsed emerging from the cloud of altercation at several places simultaneously. This effect is common as well among bodies that are spinning or being throttled. A `wacky' character has the option of self- replication only at manic high speeds and may ricochet off walls to achieve the velocity required.

Cartoon Law VII
Certain bodies can pass through solid walls painted to resemble tunnel entrances; others cannot.
NOTE : This trompe l'oeil inconsistency has baffled generations, but at least it is known that whoever paints an entrance on a wall's surface to trick an opponent will be unable to pursue him into this theoretical space. The painter is flattened against the wall when he attempts to follow into the painting. This is ultimately a problem of art, not of science.

Cartoon Law VIII
Any violent rearrangement of feline matter is impermanent.
EXAMPLE : Cartoon cats possess even more deaths than the traditional nine lives might comfortably afford. They can be decimated, spliced, splayed, accordion-pleated, spindled, or disassembled, but they cannot be destroyed. After a few moments of blinking self pity, they reinflate, elongate, snap back, or solidify.

Corollary : A cat will assume the shape of its container.

Cartoon Law IX
Everything falls faster than an anvil.

Cartoon Law X
For every vengeance there is an equal and opposite revengeance.
NOTE :This is the one law of animated cartoon motion that also applies to the physical world at large. For that reason, we need the relief of watching it happen to a duck instead.

Cartoon Law Amendment A
A sharp object will always propel a character upward.
NOTE : When poked (usually in the buttocks) with a sharp object (usually a pin), a character will defy gravity by shooting straight up, with great velocity.

Cartoon Law Amendment B
The laws of object permanence are nullified for "cool" characters.
EXAMPLE : Characters who are intended to be "cool" can make previously nonexistent objects appear from behind their backs at will. For instance, the Road Runner can materialize signs to express himself without speaking.

Cartoon Law Amendment C
Explosive weapons cannot cause fatal injuries.
They merely turn characters temporarily black and smoky.

Cartoon Law Amendment D
Gravity is transmitted by slow-moving waves of large wavelengths.
NOTE : Their operation can be witnessed by observing the behavior of a canine suspended over a large vertical drop. Its feet will begin to fall first, causing its legs to stretch. As the wave reaches its torso, that part will begin to fall, causing the neck to stretch. As the head begins to fall, tension is released and the canine will resume its regular proportions until such time as it strikes the ground.

Cartoon Law Amendment E
Dynamite is spontaneously generated in "C-spaces" (spaces in which cartoon laws hold).
NOTE : The process is analogous to steady-state theories of the universe which postulated that the tensions involved in maintaining a space would cause the creation of hydrogen from nothing. Dynamite quanta are quite large (stick sized) and unstable (lit). Such quanta are attracted to psychic forces generated by feelings of distress in "cool" characters (see Amendment B, which may be a special case of this law), who are able to use said quanta to their advantage. One may imagine C-spaces where all matter and energy result from primal masses of dynamite exploding. A big bang indeed.

Digital Timers on a Shoestring Budget
by Tony Wayne
Have you seen those timers in catalogs that digitally can time events for up to 1/1000 of a second. If you are willing to only measure down to the 100th's you can save $100's of dollars per station.
Buy a cheap stopwatch. Oriental Trading company sells one for $3.00.
Unscrew the back and take out the start stop button.
Use a voltmeter to determine which button connection is positive and negative.
Solder an 8 inch red wire to the positive connection and an 8 inch black wire to the negative connection.
Now it is up to you to make the on-off switches.
A future issue of the newsletter will include how to make a simple infrared photogate system.
Below is an example of a no contact switch that has been successfully used.


Below is an example of how I used the watch to create a no contact on-off timing system. This system will be demonstrated at the VIP meeting on Oct 8, 1994.

Sources : Neodymium Magnets from; All Electronics Corp., P.O. Box 567, Van Nuys, CA 91408-1567
Ph 1-800-826-2653. (They are about the size of a penny and $1.25 each)
Cheap stop watches; Oriental Trading Company, PO box 2308, Omaha, NE, 68103-2308,
Ph 1-800-228-2269




RESULTS OF THE SPRING 1994 PHYSICS OLYMPICS
by Brion Patterson

School Grand Winners:
First: Rappahannock Co High 579 points
Second: McLean High
Third: Tunstall High
Fourth: Chancellor High
Fifth: Charlottesville High
Sixth: L C Bird High


Paper Tower Event: LEGO Distance Derby Event:

First: Rappahannock Co High 151 cm First: Parry McCluer High 578 cm
Second: Evangel Christian 135 Second: King George High 525
Third: L C Bird High 78 Third: McLean High 446

Paper Aluminum Foil Barge Event: Fermi Questions Event:

First: Chancellor High First: Tunstall High 11 pts
Second: .Nelson Co High Second: Charlottesville High 9.25
Third: L C Bird High Third: Rappahannock Co High 8.7
Rappahannock Co High

Center of Mass Event: Table Top Cannon Event:

First: Broad Run High 72.8 cm First: McLean High 0 cm total miss/100%
Second: Spotsylvania Hig 68.9 Second: Montclair Gifted Ed Center 92.7%
Third: Musselman High 67.3 Third: Broad Run High 91.5%

Ping Pong Launch Event:

First: Rappahannock Co High 610 cm
Second: John Pattie Elementary 364
Third: J Hayden Johnson Junior High 210

School Tower Boat Mass LEGO Fer Cann Pong TOTAL

Broad Run High ... 89 100 47 13 92 0 341
Chancellor High 45 100 92 23 77 85 0 422
Charlottesville High ... 57 74 75 84 72 30 392
Evangel Christian 89 32 ... ... ... ... ... 121
Fleetwood Elem ... 61 71 11 ... ... ... 143
Indian River High ... 89 ... 39 ... ... 30 158
J H Johnson Jr High ... 79 ... ... ... ... 34 113
John Pattie Elem ... 75 ... 7 ... ... 60 142
King George High ... 45 78 91 69 58 ... 341
L. C. Bird High 52 96 76 43 43 62 8 380
Lovingston Elem ... 55 87 36 ... ... ... 178
McLean High 40 95 79 77 55 100 19 465
Montclair Gifted Center 7 54 69 25 ... 93 ... 248
Musselman High 5 45 92 38 ... 78 ... 258
Nelson Co High 6 98 83 ... 36 87 2 312
Nelson Co Middle ... 91 71 47 59 70 ... 338
Parry McCluer High ... 36 ... 100 ... ... ... 136
Peabody Middle ... ... ... 27 ... ... ... 27
Rappahannock Co High 100 96 77 41 79 86 100 579
Rosemont Middle ... 82 72 36 ... ... ... 190
Spotsylvania High ... ... 95 ... 64 ... ... 159
St. Matthews ... ... 83 36 ... ... ... 119
Tandem 5 59 78 23 64 ... ... 229
Tunstall High 46 48 91 53 100 91 8 437
Warrenton Jr High 19 61 86 ... 36 28 ... 230
Wetsel Middle ... ... 87 43 ... ... ... 130


EDITOR

Tony Wayne
PUBLISHED by
Dr. Bascom Deaver, Physics Department, University of Virginia, Charlottesville, VA 22901

OCTOBER 8, 1994, SATURDAY
AGENDA

 9:00 -  9:30 Hello's ...Coffee and donuts provided by UVa
 9:30	- 10:00 VIP Business
10:00 - 10:15 What VaPEN will look like in the future (...next year?)
10:15 - 12:00 Image collection and analysis on a MAC
              H.I.P. physics (CD ROM motion analysis and more)
              by Dr. Bob Kolvoord (author, editor and more of
              *H.I.P. Physics*.) 
12:00 -  1:30 Lunch (You will have to provide your own lunch ...restaurants are near 
by.)
 1:00 -  1:30 Collect freebies: catalogs, demo write-ups, lab tips and more, (over 
laps
              lunch).
 1:30 -  3:30 PASCO Scientific presentation: "Computer Usage in the Lab"
 
 

If you are going to the October 8 VIP meeting you need to fill out and mail the form below.
UVa needs this form for 3 reasons. So they will know: