PASCO WA-9854 Economy Wave Driver - Manual (Page 4)

Economy Wave Driver 012-08775
4 ®
Introduction
The WA-9854 Economy Wave Driver is designed to provide a low-
cost solution for the study of mechanical wave phenomena. The driver
features a 5¼" speaker which is capable of very low frequencies,
making it ideal for string vibration. A molded plastic post is attached
directly to the cone of the speaker and the wave cord is fed through the
grove on the top of the post. The two ends of the cord are tied off or
held with suspended masses. Using the included power supply,
students can drive the speaker at a constant 60 Hz and vary the tension
to create various standing wave patterns.
The Economy Wave Driver can also be driven with the Sine Wave
Generator (WA-9867) for experiments in which the frequency and
amplitude are varied. In general, the Economy Wave Driver can be
used with any function generator which outputs 0 – 7 Volts and Wave
Driver Post 0.3 – 0.6 Amps. The operating frequency for the driver is
0 – 90 Hz.
Equipment Setup to Determine the Effect
of Tension on Wave Speed
Using the included power supply, the Economy Wave Driver can be
driven at a constant (60 Hz) frequency. The tension can then be varied
and the wave velocity calculated for each trial.
1. Tie one end of the elastic cord to a table clamp or ring stand.
2. Place the wave driver on a tabletop and pass the elastic cord
through the grove on the post.
3. Tie the other end to a mass and hang the cord over a pulley about 3
meters away.
4. Plug the power supply in and begin generating waves in the cord.
5. Using your hand raise the mass until it is just over the pulley;
count the number of standing waves.
6. Calculate the wavelength with the following equation:
l =
length of vibrating string
number of waves