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Re: Ealing 3.75m air track VS Pasco tracks??

Phys-L friends,

How many of you still have and use the old Ealing
3.75m air tracks sold circa 1970??

We still have 2 in our department that are used every
semester in our demonstrations in the lecture courses.
While the air tracks are still operational, we must
always adjust the levelness of the track by adjusting
the bolts that are attached to the I-beam support. The
track gets a lot of milage because we have to move it
from the first floor to the second floor and back a few
times a semester. Another thing we do is file corners of
the gliders
after they are dropped on the floor during the demonstration.
Still, this track is an excellent demonstration.

I have noticed that Pasco sells a long track on which friction-less
carts ride on and basically do the things that the Ealing air
track can do.

Does anyone have any experiences to share about the Pasco track and
any recommendations??


Santos Ramirez
Physics Department
Texas A&M University
College Station, TX USA

The Ealing tracks are now manufacured by Daedalon (See any Announcer or TPT
for their ads), and are essentially the same design as the ones you have.
They are devilishly difficult to keep aligned, although Daedalon has a
fairly simple system using a wire strung between the ends of the track just
above the spine of a glider that can be used as a guide for leveling. It's
still a difficult process, however, and only precise to within a millimeter
or so. I have recently seen a technique that may be a little easier to use,
using a sonic ranger with the output presented on a graph of velocity vs.
position. If you let the glider make several trips along the track by
bouncing off each end, the density of points on the graphical presentation
should indicate the high and low points on the track (higher density when
it is going slower and lower density when it is going faster, and then the
points where it is going slower represent high points and so forth). I
haven't had time to check this out yet, but if it does work, it should
provide a relatively easy way to locate the high and low points on the
Ealing (Daedalon) tracks.

We also have obtained one Pasco track. Since we have ony the one, it
doesn't get used nearly as much and the others, but it seems to have lots
of advantages. It is lighter and more compact, making it easier to move
around. It requires no alignment-Pasco says that if it ever needs
alignment, return it to them for service. It comes with a double spark-wire
system which allows the recording of motion in both directions of the two
gliders in a collision, on a single spark tape-almost as good as being able
to rig up sonic rangers at each end of a track to record the complete
collision process. The gliders come with places to add weights so that the
mass of the gliders can be varied (OK, no snide remarks about "weight" and
"mass." I know the difference and I assume the reasers on this list do
also, so I feel free to use the common terms and assume that the reasers
will know to what I refer.). In general, I would say that the Pasco tracks
are superior in design, but I haven't used them enough to be able to say
whether their superficial superiority holds up under day-to-day abuse by


Hugh Haskell

Instructor of Physics, NC School of Science and Mathematics
P. O. Box 2418, Durham, NC 27715
(919) 286-3366

The box said "Requires Windows 95 or better." So I bought a Macintosh.