PASCO WA-9612 RESONANCE TUBE - Manual (Page 24)

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Resonance Tube 012-03541E
Experiment 2: Standing Waves in a Tube
Notes on Procedure
➀➁ If you have already done experiment 1, use the
known open-tube resonant frequencies from that
experiment.
➂ The node points near the open ends of the tube may
actually be located beyond the ends, outside of the
tube.
Notes on Analysis
➀➁ The wave activity pattern will be similar to the
diagrams in the “theory” section of the manual, ex-
cept that the microphone detects pressure variation
rather than displacement variation. Because of this,
the standing wave pattern will be shifted 90° from
the pattern shown.
Displacement representation
Pressure representation
Displacement representation
Pressure representation
The Theory section of the manual shows the
displacement representation for the open and closed
tubes; but the microphone will see the pressure
representation.
➂ The velocity of the sound wave inside the tube is
theoretically higher than outside the tube; but
within the limits of this experiment they will be the
same.
➃ The pressure wave reflects without inversion at the
face of the piston. It reflects with an inversion at
the open end of the tube.