3B Scientific Accessories for Rope Waves - Manual (Page 2)

Elwe Didactic GmbH • Steinfelsstr. 6 • 08248 Klingenthal • Germany • www.elwedidactic.com
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com
Subject to technical amendment
© Copyright 2010 3B Scientific GmbH
5. Operation
5.1 Set-up
• Screw the stand rod into the base plate.
• Screw the deflection device and the holder for the
dynamometer onto the stand rod and clamp them
in position.
• Hang the dynamometer on the holder. If
necessary, first calibrate the zero point.
• Connect the function generator to the vibration
generator.
• Attach the rubber rope to the vibration generator,
pass it under the deflection device then upwards,
and hang it on the dynamometer. Ensure that it
runs as parallel as possible to the base plate. The
length of the rope when stretched should be
between 50 cm and 70 cm.
5.2 Experiment procedure
• Apply tension to the rubber rope by moving the
dynamometer.
• On the function generator, select the “sine” wave-
form and the 3 kHz frequency range.
• Adjust the frequency until 4 vibration loops are
obtained.
The wavelength is now half the length of the cord.
• Move the dynamometer higher up the rod until
the tension is four times the previous value.
The band now vibrates with just one peak and one
trough. The wavelength is therefore equal to the
length of the band.
The following parameters are found to give good
results:
Rope length (= distance from vibration generator to
deflection device): 60 cm, Frequency; approx. 44 Hz,
initial cord tension: 0.5 N
Rope length: 70 cm, Frequency; approx. 38 Hz, initial
cord tension: 0.5 N
U8556001
Vibration generator
U21015
3 kHz
Frequency Amplitude
44 Hz
Fig. 1 Experiment set-up