| ISPP REMINDER |
JUNE, 2006
|
OUR
NEXT MEETING...
|
...is at the Museum of Science and Industry
|
Tuesday
|
June
6,
2006
|
6:30-8:30
PM
|
FALL, 2006
|
CSAAPT, New
Trier High School |
AT OUR LAST
MEETING . . .
Paul Dolan (Northeastern
Illinois University)
began the
meeting with an activity rather
than a demonstration. We each received
four sheets of copier paper; green, pink, blue, and brown.
The green sheet had a half life of 2 minutes,
the pink sheet 5 minutes, the blue sheet 15 minutes and the brown sheet
one
day. Paul started a
clock and explained the activity. After
every two minutes we were to tear the green sheet in half.
After every 5 minutes the pink sheet, and
every 15 minutes the blue sheet.
We
then
shifted
to announcements, with Paul
interrupting every couple minutes to announce the
time. We sang “Happy Birthday” to Earl Zwicker, and welcomed Eunjeong Son,
a graduate student from
DePaul, who was attending her first meeting. By the end of
the announcements we were down to a small piece of green and a quarter
sheet of
pink. Paul then told us we could quit as
the process of radioactive decay was well illustrated.
|
Tom Senior (New Trier High School) brought out one of the
stadium horns
made out of PVC pipe and film canisters. 35mm
film canisters are beginning to be hard to find so
there was a
discussion of what could substitute. It’s
a problem because Tom likes all his students to make
one so he goes
through a lot of canisters.
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|
He brought a
couple speakers in an enclosure that he used to break a piece of glass. He used a 16 x 2 inch piece of glass that he
suspended on two strings over a 6x6x17 inch wooden box with a hole in
the
top. At each end of the box was a 4 inch
40 watt speaker wired out of phase with each other.
He used a laser level (Menards $4) to reflect
off the top of the glass and then changed the frequency until he hit a
resonance around 79 Hz. We could see the
laser dot on the wall form a line about 20cm long at resonance. Tom
turned up the volume and the line got
longer. I expected the glass to break
and Tom said it usually did. But this
one didn’t. He turned it off and scored
the glass with the point of a screwdriver and it quickly broke the
second try.
Tom
also had
some videos and websites he got from Nick
Drozdorff (New
Trier High
School). One
was of throat singers which I must say is
an acquired taste. The other was a pair
of hands. The person (who clearly had
too much time on his hands) had learned to squeeze his palms together
and make
a noise reminiscent of passing gas. By
changing the pitch he managed to play “Hail to the Chief.”
Tom passed out the websites for these and I’m
sure if you ask him when you see him, he’ll give you a copy. Nick found them by Googling .
<>Bill Blunk (Joliet High School,
retired) had a couple
stories. A person delivering a load of
plywood did it by popping the clutch and pulling the truck out from
under the
load. This is his favorite story for Newton’s 1st
Law. Then he showed a couple slides of
people releasing a grizzly bear. One
person stood on the cage and released the bear from the flatbed of a
pickup
truck. When the bear attacked the truck,
the driver pulled away spilling the cage and the person who released
the bear
to the ground. Bill had slides for all
of us.
Larry Alofs (Kenwood
Academy,
retired) brought an
infra red thermometer he got from Harbor Freight ($19.99) and a pass
out sheet
with lots of good tips for using it. The
temperature it reads depends on the emissivity of the surface. He took out a metal container with green
sides and a shiny aluminum bottom. Then
he put some black tape on one of the sides. The can sides
and the tape read 72o or 73o, while the shiny
bottom read
79o. <>Then he
put some
hot water in the can from the coffee table and the tape and green side
read 145o
but the bottom still read 79o.
That’s because it was not emitting but was reflecting from the
room. What about ice water?
Larry tried the sides and bottom of a coke
can from the coffee table but I didn’t get the measurements.
Bill
Shanks (Joliet
Central High School,
retired) brought
a small fan with pulsing LEDs
that he got a Walgreens ($2.50). It was
kind of nice.
|
His
more
interesting demo came from the Stray Cats in the May Physics
Teacher. He put two
strong disc magnets on the sides of a triple A battery and then placed
it on a
shiny copper plate. The magnets had like
poles outward. After a few minutes of
fooling around with it (and replacing the battery) the little motor
rolled down
the copper strip. We were all a little
surprised it actually worked.
|
|
Martha Lietz (Niles West High School)
brought
out a page of E&M Tipers from
Pearson/Prentice Hall, a book of ranking tasks. Martha
demonstrated the magnet going into the ring. She
asks her class to rank when the force
pushing the ring will be greatest and she lets the speed of the magnet
and the
polarity of the magnet change. She also
cuts the ring.
Martha
says her
students enjoy discussing the ranking tasks and she suggests everyone
try
them. She also suggests that sometimes
it’s a good idea to reduce the variables so you can see exactly where
the
students are having trouble.
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|
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Gerry Lietz (DePaul University) brought his jumping ring
demonstration. He runs it on 120V AC but
uses an isolation transformer so no one who touches his knife switch
will be
electrocuted. He followed Martha with a
coil with a light bulb attached. When he
put the coil over the bar, the bulb lit. Then
he put the coil in a beaker and added water. When
he put the beaker over the coil the bulb
lit under water.
Gerry followed
with a series of demonstrations you could do. You
can boil water in a coil, get a coil spring with
contacts that will
bounce up and down, or cool the ring in liquid nitrogen and watch it
jump much
higher. Gerry also had a circular copper
plate pivoted on its axis and a second plate. Holding
one plate partially over the rod he could bring
the pivoted
plate near it and cause it to spin. <>
A discussion of
the phase difference between the ring and the pole followed. Gerry passed out sheets with explanations and
graphs that I haven’t had a chance to read yet, but they look really
interesting.
|
|
Rich DeCoster (Niles
West High
School)
blew into a
root beer bottle and got a
nice deep hum. He used the thin tube
closed at one end formula to find the frequency and got an answer that
was
almost exactly twice what he observed. Rich
said
it’s not a cylinder but a Helmholtz
resonator.
The frequency equation is
where 
<>
is
the speed of sound, 
is
the length of the neck, Vtop,
the volume of the
neck, and Vbottom
the volume of the bottle below the neck. The
answer comes out to just about half the
cylinder answer for this particular bottle but that’s just a
coincidence.
Art Schmidt (Northwestern
University)
brought out
the give
away. He had some of those small tops
you spin between your finger and thumb.
If you do it right they turn over and spin on their stem.
Art
also had
some 3D glasses. These really
worked! I looked at Jerry’s graphs and
the red line almost jumped off the page.
Art shined a green laser through the glasses and we got many
orders, but
the laser shifted left or right when it was sent through one lens or
the
other. We didn’t have time to discuss
how it actually worked. (It was left as
a problem for the student). I’ve been
playing with my glasses for the last couple of days.
Come
to the
Museum
of Science and
Industry next month and
maybe we will have time to talk about them.
And find out who wins this year’s John Rush Award.
<>
Submitted
by Pete
Insley
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
Happy
Birthday, Earl
and
Thanks
for many years
of PHYSICS PHUN
|
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BRING FRIENDS
BRING IDEAS ! !
SEE YOU THERE ! ! !
Roy Coleman
|
Pete Insley
|
Earl Zwicker
|
Tom Senior
|
Gerry Lietz/John
Milton
|
Debbie Lojkutz/Erik
Jergens
|
Gordon Ramsey
|
Ruth Goehmann
|
Paul Dolan/Joe
Hermanek
|
Art Schmidt
|
Van Bistrow/Dennis Gordon
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During 2005-06
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Coordinators: Paul
Dolan
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ISPP Authors: Art Schmidt
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Data Base Managers: Roy Coleman
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Gerry Lietz
|
John Milton
|
Earl Zwicker
|
Earl Zwicker
|
Pete Insley
|
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Photographers: Paul Dolan
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Treasurers:
Ann Brandon
|
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Art Schmidt
|
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Gerry Lietz
|
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John Milton
|
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Earl Zwicker
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<>
Special
Events Committees:
|
Physics Day - Ann Brandon, Roy
Coleman (C-Chairs)
|
John Rush Award - Debbie Lojkutz
(chair), Eileen iWild, Nate Unterman, Bill Blunk (ex-officio)
|
Harald jensen Award - Keith
bellof (chair), Martha leitz, Ann Brandon
|
Annual Tri-Physics meeting -
Evan Richards, Matt Lowry, Gerry Lietz
|
National Bridge Building
Committee - Carlo Segre
|
New member Committee - Kevin
McCarron (coordinator), Ann Brandon, Pete Insley, John Milton
|
DIRECTIONS TO THE MUSEUM
From the north,
head south on Lake Shore
Drive and turn right onto 57th Street.
Get in
the left lane and follow 57th
Street around to the Museum's west side.
Turn left
to enter the Museum's underground garage.
From the south,
Due to renovation and construction on I-94
(Dan Ryan Expressway), we recommend northbound drivers use the
following
detour. Take the
East
103rd Street/
Stony Island Ave.
exit off of I-94 West.
Follow
Stony Island Ave. northbound and take a
right at
57th Street,
which
will lead you into the Museum's underground parking garage. If you are
north of
103rd Street,
take
Stony
Island and follow
it to
57th Street.
"
Alternate Route"
signs will be posted throughout I-94 work zones to direct travelers to
alternate routes.
From the west, follow 290 East
or 55 North to
Lake Shore
Drive.
Go south on
Lake Shore
Drive.
Exit right on
57th Drive.
You'll need to be in the left-hand lane as you follow the curve around
to the
west side of the building and
Cornell Drive. Turn left to enter
the Museum's underground
garage.
