VIPs mission is
to foster communication among teachers of
physics and physical science as well as to provide unique learning
teachers and their students.
here to go to the main page for the Virginia Instructors of
Next Meeting March 25, 2000, at
UVAs Physics Building
here to download this entire newsletter as an Acrobat Reader
A note from the President
Hi! I hope this newsletter finds you in good
health and good spirits. For many of you this may be the first time
you have received a mailing from VIP. If this is the case let me take
a little of your time to introduce myself and the organization. My
name is Andy Jackson and I teach Physics and Astronomy(new
class-First year!) at Harrisonburg High School. I have a BS in
Physics from James Madison University and have been teaching for 13
years now. VIP has been instrumental in providing me with excitement
and growth opportunities in Physics education. VIP is a (very!)
loosely organized group of teachers, professors, and educational
staff who are interested in physics and the teaching of physics. This
letter has come to you because someone in your schools central office
identified you as a physics teacher or you have at some past time put
your name on our mailing list.
This organization was created about 13 or 14 years
ago as a means for physics educators to get together to share ideas
about teaching physics. We meet twice a year to share labs, demos,
concerns and questions about teaching physics. This newsletter is an
additional means for trading labs and demos. Our last meeting was
held in conjunction with the Fall VAST meeting that was held in
Richmond. Our session was well attended and I got to meet a lot of
physics teachers from around the state and beyond for the first time.
I hope if you were one of those I had the privilege of meeting, you
will consider attending our spring meeting at UVA Saturday March 25,
2000. If youre a VIP veteran than you know what its all
about and I hope to see you again in Charlottesville in the
Looking forward to seeing you at UVA on March 25,
Andy Jackson firstname.lastname@example.org or email@example.com
Harrisonburg High School Science Dept (540) 434-4923
395 South High Street
Harrisonburg, VA 22801
If you ever find yourself in Harrisonburg Id love to see you.
If youd like to visit my classroom, you are certainly
MARCH 25, 2000, AT
UVAS PHYSICS BUILDING
SPRING MEETING SCHEDULE
9:00 - 9:30
9:30 - 10:30
VIP Business, Election of officers
10:30 - 11:30
General Demonstrations and Lessons Plans
12:00 - 1:30
Lunch (You are on your own.)
1:30 - 3:30
More general demonstrations and lesson plans
If you will be attending please contact
me. If youd like to present please
let me know how much time you would like. My e-mail, phone &
school address are above.
There is no fee and there
are no dues, just come and enjoy! Please
bring an idea, lesson plan, demo or experiment to share (~50 copies).
Also, consider bringing another teacher who might benefit.
Have a piece of equipment you dont know how to use (or what it
BRING IT !!! See if you can stump the experts (whoever they are) or
get some help.
Click here for directions
to the meeting.
The three labs that follow are my adaptations
of labs that are in PysicaAL: An Activity Approach to Physics by
Martin Spronk published by LeBel. I use these three labs very early
in the course. In fact, Aristotles law we do on day 1. Hope you
can use them.
Aristotle's Law of Falling
The Greek philosophers are generally given credit
for being the fist people to attempt to develop science. One of the
most famous of these philosophers was Aristotle. He lived in the
century of 300 B.C. and did a lot of thinking about what we today
call physics. One of the subjects that he contemplated was the nature
of falling objects. He formulated a description of the way objects
fell that became Known as Aristotle's law of falling bodies. This law
states that the rate of the fall of a body is proportional to its
weight: the heavier the body the faster it falls.
One of the main differences between the science of the ancient Greeks
and science today is that today we use experimentation to test our
ideas. Today you will conduct an experiment to test Aristotle's
To test Aristotle's law of falling
Write out the...
This is a question that will be answered
by the experiment.
MANIPULATED VARIABLES or INDEPENDENT
This is a list of the variables that you
will change in a methodical way to see how
they affect the
Remember that in a good experiment that you only want to change
one variable at a time.
This is a list of the things that you
must keep constant so they won't confuse your conclusions.
The thing that will be looked at to see
how it changes with response to changes in the independent
This is your best answer to the simple
problem that you posed earlier based on the knowledge you have
prior to doing the experiment. Remember that it is perfectly OK.
to be wrong here !
Write out what you are going to do. Make
sure you pay attention to what you have chosen to be your
manipulated variable and your controlled variables. It is good
procedure to do several trials for every change you make.
Create a data table to record your
Discuss whether your tentative answer to
the simple problem was supported or refuted. Back up your, "I was
right," or, "I was wrong" with evidence offered by the data you
collected. Write down a few questions about the nature of falling
objects that still remain.
- If you found that Aristotle's law was not
correct state what you now believe is the correct law for falling
- Aristotle's law was taught as "...for many
centuries in Europe's leading universities. Why was it believed
for so long?
- Does this experiment shed any light on why
rocks fall faster than feathers? Why or why not?
Notes to the teacher
What I like about this lab is, right off the bat,
the students are talking, discussing and thinking Physics! Enjoy
watching the students. Some still believe Aristotles law to be
true. I find this in Honors as well as general Physics. I use this as
a platform to talk about experimental design as well as a vocabulary
builder. At the end of the class I conduct experiments in front of
the class so everyone leaves with the right data. Some
groups will have data that supports Aristotles law due to
strongly held notions of falling bodies. Andy
Notes to the teacher
This next lab is also my adaptation of
PhysicALs version of an oldie but a goody. The results are
reliable and it uses pretty standard equipment. The quote by Galileo
at the top of the lab is something I try to incorporate into all my
labs. A famous quote that has some pertinence to the question at
hand. I have students keep a Physics Journal, and as a small grade
assignment, I have them write about the meanings of these quotes.
What was Galileo talking about? Is it possible for people to see
beauty in facts? Do you agree or disagree with what the
quote is saying? As I read the students responses I often get some
neat insights into their thinking.
This lab is also a beginning point in the class for presenting and
interpreting graphs. At this point in the course, we have already
completed a measurement & sig. fig. lab. The students are
expected to be able to measure carefully and correctly at this point.
In addition to the uniform acceleration topic being introduced here,
I take the opportunity to introduce the concepts of random and
systematic error as well as the difference between errors and
Motion of a Falling
Facts which at first seem improbable will, even on
scant explanation, drop the cloak which has hidden them and stand
forth in naked and simple beauty.
- to apply measuring skills and graphing skills
to the analysis of a ticker tape created by a falling
- to determine the manner in which a falling
body's displacement changes over time.
- ticker timer
- meter stick
- masking tape
- Attach a ticker timer to the top of a support
stand and place the set up on the counter top.
- Tear off a piece of ticker timer tape that is
just a little shorter than the height of the timer from the floor.
Ticker tape is expensive use it intelligently.
- Feed one end through the timer and tape it to
- Place newspapers on the floor to cushion the
- Spread the tape out so that it does not tangle
as the mass falls.
- Hold the mass very still , turn on the timer,
release the mass.
- Turn off the timer and check to see that you
have a good record.
- Create a tape for each member of your
- Keep your tape until this and the next lab are
graded & returned to you. I may ask to see it.
- Identify the dot that was made when the mass
was released. Mark this on the tape as t=0.
- Your timer makes 10 dots each second. Mark
each dot after the t= 0 dot as 0.10 s, 0.20 s etc.
- Measure the total distance the mass has fallen
for every tenth of a second. This means that you will measure the
distance to each marked dot starting from the zero
- Make a table of the data. Remember to measure
carefully and use proper significant figures. The table should
have time and distance in it.
- Construct a distance vs time graph for the
motion. Make a smooth curve through the distribution of data
points that is representative of the motion.
- What does the increasing slope of the graph
indicate about the nature of a falling object?
- If a serious error or mistake occurred in the
measuring of a single data point, would it be more easily spotted
in the table or on the graph? Why?
- When two or more trials of a measurement
differ slightly from each other the cause of the difference is a
random error. Random errors can be due to errors in judgment by
the reader, fluctuating conditions, small disturbances in the
environment or equipment, or irregularity of the object being
measured. When all of the measurements deviate from the known
value by the same amount then this is most likely a systematic
error.These can be due to errors in calibration of the instrument,
constant experimental conditions different from those assumed, or
consistently imperfect technique.
We know there is a certain amount of friction
between the tape and the timer. Does this introduce a random error or
systematic error? Defend your answer. When you are measuring the
distance from one dot to the next, how far off from the
correct value can you expect to be? In other words what
is the uncertainty in your measurements? Is this + or - value
systematic or random error? Defend your
Expected Lab Answers for Motion of a Falling
The graph for D vs T for this experiment should
look something like this
D The increasing slope is indicating the object is falling a greater
distance in each 1/10 th of a second. Many students will correctly go
the next step and identify this as the object is falling faster the
longer it falls.
#2- I expect most students to respond that it is easier to see on the
graph since the point in question wont line up with the rest on
the curve. Some students can convince me otherwise with a well
explained explanation for their answer.
#3 - Friction between the tape and timer is a
systematic error. It affects every trial and every dot made. The
uncertainty in each measurement is indicative of random error.
Someone might measure slightly long while the next person
might measure slightly short.
Speed of a Falling
Simple Problem- How does
the speed of a falling body change over time?
- ticker tape from the previous lab
- Measure the distance the mass fell between
each time interval. This is called the interval
- Fill in the data table below.
- d -
Speed of a falling
- Youll notice that the distance for each
interval is getting bigger and bigger. Since each interval
corresponds to 1/10 of a second what does this mean about the
speed of the falling body?
- At what point in time will the instantaneous
speed of the mass be equal to the average speed of the mass during
a particular time interval? Consider the beginning, middle, and
end times. Defend your answer.
- Use graphical analysis to construct a graph of
speed vs time.
- What does the shape of this graph tell you
about the manner in which a falling object gains
- What is the equation for the Best
fit line or curve. Write this equation including the correct
- If you used a ticker timer that had more
friction in what ways would the graph be different?
[HINT write about the way the line on the graph would
Notes to the teacher
Yet one more adapted from the same source Spronks
To complete this last of the falling body labs, the student needs to
be comfortable with the concepts of average speed and instantaneous
speed. Between the Motion of a Falling Body and the Speed of a
Falling Body labs, I spend a class period with some reading, lecture,
and group labs calculating speeds for walking, running
and other motions.
#1 The speed is increasing.
#2 The average speed equals the instantaneous speed at the middle
time. At the start it is going slower than average and at the end it
is going faster than the average since it is picking up speed the
#3 This should be a straight line graph passing through the
#6 The object would gain speed at a lesser rate so the slope would be
less. The line would lay closer to the x-axis.
Here is an item that definitely departs from the VIP
status quo. This is not a lab or demo but notes for a lecture that I
have found to be very interesting to myself and to my
students-especially those more inclined to the humanities than the
sciences. This lecture concerns the interesting and famous conflict
between Galvani and Volta that eventually led to Voltas
creation of the precursors to our modern batteries. Also included in
the lecture is some conjecturing about links between Galvani, Volta
and the famous novel by Mary Shelley, Frankenstein. Ive cited
my sources and Im sure you can gain much more from them than
from my notes. Ive found it to be a great point to do some
interdisciplinary teaching. Andy Jackson
Of Frogs and
(Notes for Literature and Physics cross curricular
lesson by Andrew S. Jackson)
Franklin publishes book on electricity in mid
1700s that was later translated into Italian.
Luigi Galvani is professor of Anatomy &
surgery at Bologna.
Galvanis particular interest is animal
senses. He believed Franklins description of Leyden jars to be
most important. He noticed that frog muscle twitched when subjected
to a spark. It was already known that living muscles spasm but now he
saw dead muscle react! He knew (by Franklin) that lightning was
electricity set out to see if lightning would make dead muscle
twitch. Galvani hung frogs legs on brass hooks so they rested against
iron window lattice. The muscles twitched in thunderstorm and in
clear weather. Galvani thought muscles acted like leyden jar where
the nerve and the muscle acted as the two surfaces. He concluded that
the electricity was in the muscle and called it animal
(a print from Immortals of Science - Alessandro Volta and the
Electric Battery by Bern Dibner showing Galvani at work)
Galvani published his ideas in Proceedings
of the Bologna academy of Science in 1791. He printed a small
number of pamphlets for friends. He sent one to Alessandro Volta,
Professor of Physics at University of Pavia.
Volta repeated the experiments but suspected
Galvanis hypothesis was incorrect. Volta decided the
electricity was created by the two metals & the muscle was just
an indicator of its presence.
Volta published Account of some discoveries
made by Mr. Galvani in 1793. He praised the discovery and
tentatively suggested his ideas. In 1794 he published stronger
arguments against Galvanis hypothesis.
Galvani was shy and steered away from argument and
controversy & was silent on the matter. Galvanis supporters
argued on his behalf. Particularly vocal was Giovanni Aldini
(Galvanis nephew) Professor of Physics at Bologna.
The two cities which were about 100 miles apart
took sides as did the rest of the scientific world.
Aldini was more of a showman than scientist and
did public demonstrations with slaughtered animals and severed heads,
and limbs of executed criminals.
In 1797 Galvani still believed his ideas were
valid and went to the Mediterranean to study the torpedo( an electric
eel of sorts) He was requested by the invading French to sign an oath
of loyalty to the new republic. He refused.
Galvani suffered academic and political setbacks
and died in 1798 sad and disillusioned.
Mary Wollstonecraft Shelley
Marry Wollstonecraft born 1797 in England.
At the age of 17 in 1814 She eloped with Percy
Byshe Shelley to Europe.
While visiting Germany they may have visited the
One June 16 1816 Mary and Percy stayed at Lord
Byrons place on lake Geneva with Lord Byron and Polidori,
Byrons personal physician. One discussion that took place
concerned the Nature of the principle of life (intro to
3rd edition Frankenstein) They spoke of some recent experiments
conducted by Dr. Darwin (Charles Darwins father) and Mary
remembers thinking Not thus, after all, would life be given.
Perhaps a corpse would be re-animated; galvanism had given token of
such things: perhaps the component parts of a creature might be
manufactured, brought together, and endued with vital
A ghost story contest was proposed and a short
story version of Frankenstein was Mary Shelleys
contribution. (Incidentally the first version of the modern vampire
story was written by Polidori the same night!)
Mary Shelley Published Frankenstein in
In the book Victor Frankenstein says
One of the phenomena which had particularly
attracted my attention was the structure of the human frame and
indeed, any animal with life. Whence, I often asked myself, did the
principle of life proceed Chapter 4
I collected the instruments of life around me, that I might
infuse a spark of being into the lifeless being that lay at my
feet. Chapter 5
Immortals of Science - Alessandro Volta and the Electric Battery by
The 1995 Grolier Multimedia Encyclopedia
Frankenstein or The Modern Prometheus - by Mary Shelley
The History of Physics - by Isaac Asimov
The Real Frankenstein and Untold Story -(video) by Truusje Kushner
produced by Nicholas Stein. ABC Video Publishing P.O Box 3815,
Stamford CT 06905
This next lab is sent in by Thomas ONeill (VIP vice president).
Its a great experiment
that can be quite fascinating. (And who can resist the smell of Play
Doh?) There can be
some additional but puzzling extensions to this experiment as
sometimes the play dohs
resistivity doesnt always behave the way you think it should.
You might even see if resistivity is color dependent. Thanks
The Play DohTM
by Thomas ONeill
The student will demonstrate knowledge of the relationship between
length of a wire and resistance of a wire by experimental determining
that relationship using a Volt-Ohm meter.
The student will demonstrate knowledge of the relationship between
cross-sectional area of a wire and resistance of a wire by
experimental determining that relationship using a Volt-Ohm
VA SOL - 3rd 3.3, 3.4, 3.5 4th 4.4, 4.7 6th 6.2 8th 8.1, 8.4, 8.9,
12th 12.1, 12.3, 12.11, 12.16
Equipment and Materials
Play-DohTM modeling compound, Volt meter, ammeter
Play DohTM modeling compound, Volt-Ohm Meter(VOM)
Carpenter, Rae and Minnix, Richard. The Dick and Rae Physics Demo
Notebook. Dick and Rae, Inc. 1993 pg E-380
Jones, Brian. resistance Measurements in Play-DohTM. The
Physics Teacher 31:1 (Jan 1993) pp. 48-49
Construction of equipment:
The Play DohTM should be fresh and not dried out. Shape the material
into a cylinder. Set up the Volt meter and ammeter as diagramed
below: The power should be supplied by a 0-15 V lab DC source. The
Volt meter should be connected across the ends of the Play DohTM and
not the leads of the power supply as chemical reactions at the
interface of electrode and Play DohTM will rapidly change the
character of those ends.
Alternatively, with a good VOM it is possible to measure the
resistance directly although the numbers will vary considerably and
will not be consistent with the Volt/ammeter method. Small fissures
in the Play-DohTM will have large effects on the internal resistance
of the cylinder. It is usually best to plot only the results from one
run (constantly increasing the length) as the resistance of the
cylinder seems to depend on the presence or absence of cracks in the
Play-DohTM as it is rolled out.
1) Measure the resistance of the Play-DohTM for various lengths using
the same amount of compound each time.
The general equation for resistance of a wire is
where R is the resistance, is the resistivity and is characteristic of a given material (usually
in Ohm-cm), length is the length of the wire in cm and area is the
cross sectional area of the wire in square cm. Since the volume of
the cylinder in question is constant and
then substituting in the above equation we get
and Volume are constants. This means that a plot of resistance versus
length2 should be a straight line.
Palm Pipes, A
Handy Musical Instruments
This great demo/lab idea was submitted by Charlene Wyrick of York PA. She says it is an
adaptation from a presentation at the Central PA - AAPT workshop
given in98. Listed a compilers of the hand-out were
Patrick Callahan and George Amann. Thanks for some great
To show how the length of a tube is
related to pitch and to make a little music.
Materials and Construction:
Cut 1/2 PVC pipe to the lengths
listed in the table provided later. A complete set of 2 octaves
(15 pipes) can be made from one standard 10 foot length. Use
plastic pipe and tube cutter available from most Builders
supply and Do it Yourself type stores. The tube cutter costs about
$15 and is well worth it if you are making several sets.
Otherwise, cut the pipes a little long with a hacksaw and sand
them to remove burrs. Be sure there are no rough edges on the
The pipes can be marked using different color
tape or paint or by the letter name of the note:
F-G-A-Bb-C-D-E-F-etc. or by the frequency, using permanent marker.
Clear spray paint or clear fingernail polish will make the marker
more permanent. Or- you could leave them blank and have students
identify the note!
How to Play:
It is easier for each student musician to
play one pipe. Grasp the pipe firmly in one hand and quickly bring
it down onto the palm of the other hand, allowing the end of the
pipe to strike the palm of the other hand.
Have students practice playing the same note in unison, then try a
scale involving all.
Practice playing a sort of Chord - two notes in
Play a song
The conductor points out which not to
play. Since here are two octaves, there are two or three different
lengths for the same note. You can play the song using melody or
harmony together, or play only the melody, depending on the
ability of your students.
- Have students listen to each pipe and arrange
the pipes in order form high to low pitch.
- Ask the students to experiment to find other
ways to make sounds with the pipes(blowing, dropping, hitting,
- Have students match the pitch of the pipes to
other instruments in order to identify the note. (piano,
xylophone, tuning forks, etc)
- Have students place the pipes tightly on their
palm and blow across th e top of the pipe. How does the sound
differ from palming the pipes?
- Hold the pipes in one hand, leaving both ends
of the pipe open(not covered by hands, fingers, etc) have students
blow over the top of the pipes. How does the pitch change now?
What is the difference in the sound of the open and the closed-end
F Major Scale: F G A Bb C D
1. F F G E F G A A Bb A G G G G E F
My coun-try tis of thee sweet land of lib - er- ty of the I
2 C C C C Bb A Bb Bb Bb Bb A G
3 A Bb A G F A Bb C D Bb A G F
Twinkle, Twinkle, Little
Melody F F C C D D C Bb Bb A A G G F
Harmondy C C A A Bb Bb A G G F F E E C
Melody C C Bb Bb A A G Repeat this line
Harmony A A G G F F C
Rich McNamara & Ron Revere contribute a list
of applets to take a look at. Believe it or not this is only a
partial list! I reserved some for a future newsletter.