Information:
Don
Kanner (Lane Tech,
physics)
Physics
with MSTS:
Microsoft
Train Simulator
Don projected an image of the instrument panel of a
locomotive on the
screen at the front of the class. He used the MSTS
locomotive simulator,
which can be run on a computer to teach physics
in class. Two (brake) pressure gauges, a speedometer, a
digital clock,
a Train Status indicator, and a Force Gauge were
visible.
Don highly recommends the Print Screen™ software
program on Windows™
to save images at time
intervals from this (or any other) program to a folder of your
choice. See
also this URL: http://www.download.com/Print-Screen-Deluxe/3000-2094_4-10356546.html?tag=lst-0-2.
In addition, see the (free, downloadable) Picasa2 Picture
Editing Software: http://picasa.google.com/index.html.
These screens then can be used as a data set
to help with problems involving, for example, speed and distance
versus time,
for uniform linear acceleration, variable acceleration, and circular
motion. In particular a decrease in acceleration
for a certain locomotive automatically occurs at a speed of 45 m/s,
with a corresponding decrease in force,
explained by Newton's Second Law. This locomotive is
programmed to
accelerate more quickly at low speed, and less quickly at high speed,
to stay on
schedule. Good stuff! Thanks, Don.
Betty Roombos (Gordon Tech HS,
physics)
Explore, Plan, and ACT
Betty
recently proctored a pre-ACT Plan Test [http://www.act.org/plan/]
-- a practice test for the ACT that is often taken by 10th
graders.
Biology, weathering,
conservation of mass and water, wave-particle model with photoelectric
effect,
and centripetal force were among the topics covered.
Betty felt that this sophomore level test included topics beyond
what
the sophomores should be expected to know. She asked whether the
Plan Test was thus appropriate
for practice. Another concern
was that the students were not given enough time to reason out the
information in
the test -- which was given via complicated charts and graphs. Good
questions! Thanks, Betty.
Fred Schaal (Lane Tech HS,
mathematics)
RR on the GD (RailRoading on the Great
Divide)
Fred handed out a sheet he had gotten from a search
engine of American Orient Express [http://american-orient-express-train.com/].
He saw the name on some train coaches last summer during his western
train trip. These luxury train voyages
run on AMTRAK routes; the 2006 schedule is given on
this page: http://american-orient-express-train.com/trips.shtml.
Fred also asked why the full moon seems to hanging so low in the sky. For additional information see the NASA web page Summer Moon Illusion: http://science.nasa.gov/headlines/y2005/20jun_moonillusion.htm. Thanks, Fred.
Ann
Brandon (Retired, Joliet
West)
Halloween Math + Straw Stuff
Ann
had a roll of ticker
tape to illustrate Halloween Math -- specifically to determine
what
one gets when one divides the circumference of a pumpkin by its
diameter.
As surrogates for pumpkins we used round plastic
jar caps of various sizes. Pieces of
ticker tape the length of the circumference and the length of the
diameter were
measured and torn from the ticker tape roll. Each person then had
a diameter and a circumference for their
"pumpkin". Ann attached a magnetized
meter stick vertically to the blackboard, which was used to mark the
distances for each person's ticker tape pieces.
It also served as the Y-axis for a set of coordinates on the
board. The length of each circumference was the
Y-value and the length of each diameter the X-value
for a point
with coordinates (X,Y) -- one data point per person. This
produced
points that traced out a straight line, the slope of which was p, ie,
the function which describes the line is Y = p
X. That is, the
circumference of a circle is p times
its diameter: c = p d.
Ann also pointed out that with tape each student could tape his/her diameter strip on the X-axis, with the circumference strip taped at right angles starting at Y = 0 and the right end of the diameter strip, leaving the top of the circumference strip at the place where the corresponding point will be. Using the best fit, we calculated the slope of the line to be 64.3 cm / 20.5 cm = 3.1366! Pretty close to the real thing-- now let's eat some real Pumpkin p!
Ann then showed two old cardboard boxes filled with Swan paper straws (probably dating back to the 1970s). There are things you can do with paper straws that you cannot do with plastic straws. Paper straws are reportedly still available from a coffee supply company or at a Hard Rock Cafe™ . They can also be ordered from art supply catalogs, commonly used by art teachers in schools. She cut an inverted V into the flattened end of a straw, forming a double reed, like an oboe. Ann then blew continuously into the straw, producing an oboe-like sound. As she did this, she used scissors to cut successive pieces from the end of the straw. We heard the pitch of the sound getting higher -- usually, but not always.. Ann then showed how you can make smoke (which you may need for a demonstration with a LASER, etc) by lighting the end of the straw and letting it burn down a bit. Then she blew into the straw, causing the smoke to puff out of the lit end by squeezing the unlit end of the straw. Neat stuff, as always! Thanks, Ann.
Walter McDonald (VA and CPS substitute
teacher)
Hidden Magic Coin
Walter
handed
out a sheet which contained directions for the hidden coin trick (from Hidden
Tricks:
Playthink #613 from the book 1001 Playthinks by Ivan
Moscovich [see hs100405.html].Walter
then, with Fred's help, performed the
trick -- which worked perfectly!-- and which illustrated the
mathematical
concept of parity checking; see the Webopedia web page
What
is parity checking?: http://www.webopedia.com/TERM/P/parity_checking.html.
Walter then discussed the role of parity in
computer operation. It is used to check the accuracy of data sent
from one computer
to another.
Five coins were shaken and then scattered onto the table. Walter looked at them, and asked a volunteer to turn over any two coins, and then cover up any one coin from view. Walter then looked at the four coins in view, and told us that the hidden coin was "heads". We looked. He was right -- and we applauded Walter! Walter repeated this feat a second time, and he made us all curious to know how he did this. Marilynn Stone figured it out. You need at first to count the original number of heads and remember it. Then count the number of heads in the final configuration with one coin covered. When you then flip two coins, only the following three cases can occur:
Initial | Final | Change in #Heads |
HH | TT | - 2 |
HT | TH | 0 |
TT | HH | + 2 |
Dianna Uchida (Morgan Park HS,
computing)
Science Fair Projects
Dianna
shared an article by Emilie Le Beau that appeared in Kid
News: (11 October
2005, Chicago Tribune). It gave the following 10 tips for
preparing science fair projects --- particularly for students who
waited too long and
were short on time:
Roy Coleman (Morgan
Park HS,
physics)
Air Gyroscope made from a Bowling Ball
In 1968 Roy took a
course with Harald Jenson at Lake Forest College,
which inspired him to build an air
gyroscope [http://www.physics.umd.edu/lecdem/services/demos/demosd4/d4-10.htm]
using a bowling ball. A bowling ball (with a metal rod about
10 cm
long and 1 cm in diameter that was threaded radially into the
ball) sits
with its bottom half resting on a hemispherical plaster cast of itself
and
mounted at the top end of a metal cylinder. A vacuum cleaner is
used to
flow air into a tube leading to the bottom of the hemispherical plaster
cast. Subsequently, when the ball is placed into the hemisphere,
it is
supported on a nearly frictionless film of air flowing between
it and the
plaster. Once the ball is
rotated with the help
of a hand, it continues to spin, and it precesses and nutates
-- both are easily seen in the motion of the rod above the ball.
Roy used this project for his Masters Thesis at Loyola
University.
Roy's description of this Bowling Ball Gyroscope appeared
in the
journal The Physics Teacher [http://scitation.aip.org/content/aapt/journal/tpt]
in 1970. In a short ceremony -- and with our
applause!
-- he gave the apparatus to Debbie Lojkutz , who had used
and broken this apparatus when she was Roy's
student at Morgan Park HS some years ago. Roy
remarked
that, over the years four students had severely damaged physics
laboratory equipment --- and that all four of them have become
physics
teachers. Interesting! Thanks, Roy.
The following five people could not present lessons today, because we ran out of time. They will be scheduled first at our next SMILE meeting, Tuesday November 1. See you there!
Notes prepared by Ben Stark and Porter Johnson.