PASCO WA-9612 RESONANCE TUBE - Manual (Page 20)

Resonance Tube 012-03541E
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➂ Determine how far on the screen it is from the initial pulse to the first echo. Record this in
table 4.1. Record also the sweep speed setting (the sec/cm setting of the oscilloscope) and
the distance from the speaker to the piston.
➃ Move the piston to a new position. Note that the first echo moves, too. At the new posi-
tion, record the distance from the speaker to the piston face, the distance from the initial
pulse to the echo, and the sweep speed.
➄ Continue moving the piston until you have accumulated at least five sets of data.
➅ Now remove the piston and repeat the experiment with the open tube.
➤ Now move the microphone around to the open end of the tube. Determine how long it
takes the sound wave to travel from the speaker to the microphone.
Analysis
Use the data that you have recorded to calculate the speed of sound in the closed tube.
Assuming that the speed of sound in the open tube is equal to the speed of sound in the
closed tube (a good assumption), how long does the tube appear to be for the open tube?
How does this answer compare to the actual length of the tube? Discuss the comparison
you just made.
Describe how you might set up an experiment to determine the velocity of sound in air, not
in the tube.
TABLE 4.1 Speed of Sound in a Closed Tube
Tube Distance on Sweep Speed of
Length Scope Screen Speed Sound
TABLE 4.2 Speed of Sound in an Open Tube
Tube Distance on Sweep Speed of
Length Scope Screen Speed Sound