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Description:
Fall 2005
Ikemefuna
Agbanusi (Ike) and I built a working
foucault's pendulum in a
stairwell at NJIT. It was an official
NJIT mathclub event (e-mail
mathclub@oak.njit.edu to join
the
Pi-Landers).
Motivation:
1)
Measure the Earths rotation!
2) Observe that sin(x)=x for small angles.
3)
Test the period of a pendulum is 2*pi*sqrt(L/g)
Apparatus:
The bowling ball knocked over the black
chess pieces to its left as it made a clockwise precession. In the
southern hemisphere it would have knocked
over the white pawns
to its right.
16 pound weight, 17 Meter rope (56 feet), 8 second period (measured for
large and small amplitudes!).
Swing of about a foot after left for 25 minutes.
Thank you
Claus Holzapfel for use of your way long measuring
tape.
FAQ:
Why would I purchase a Purple
bowling ball?!
It was given to me by a stranger in a
bowling alley . . . no seriously it was.
Why chess pawns?
There weren't enough bishops.
Note: The humor in knocking over the tiny pins with a bowling ball
was not missed.
What did you do to reduce friction?
If your weight is heavy enough, most of the friction comes from the very
top. As shown in the diagram below (not to scale) the weight was
supported by the gray bar. The rope was then held slightly to the
side by the tight webbing (black circle per diagram).
The rope was able to bend with little friction at such small angles.
(The rope always stayed in contact with the webbing). |
