Measuring the Speed of Sound (Moving Tube)
Measuring the Speed of Sound (Moving Tube) KEY
Purpose: To measure the speed of sound in air using a variable length column of air.
Apparatus:
resonance-tube apparatus (an open ended tube which can be moved in and out of a container of water) constant frequency source (tuning fork or computer generated tone) rubber hammer meter stick rubber stopper
Procedure:
1. Set Up the Experiment:
Place the open ended tube into the water, and verify that it can produce a resonance tube length within the limits set by your instructor.
Confirm that you can hear the sound produced by the constant frequency source. If using a tuning fork, place it as shown in the picture, with the tuning for directly over the tube but not so close that it can vibrate and damage the tube. If using a different sound source, adapt your instructions below to your situation.
2. Find the Resonance Condition:
Starting with a very short air tube length, strike the tuning fork, place it near the tube, and increase the air column listening for a length that has a louder than normal sound. Place your ear near the top of the tube but off to the side slightly.
(If you place your ear directly over the top of the tube, you will be able to hear the “sea shell” effect and your ear will tend to make the open end a partially closed end, which will affect your results.)
Continue striking the tuning fork and raising the tube slowly until a marked increase in sound intensity is heard. Continue to refine your location until you have located the point of maximum sound intensity. This is the resonance point.
Measure the distance from the top of the water to the top of the glass tube. This is the length of the resonance length and corresponds roughly to ¼ wavelength, as shown in the diagram. Other resonance conditions may be possible if your tuning fork is matched appropriately with the tube.
Measure the temperature of the room in 0C and the inside diameter of the resonance tube.
3.
Purpose: To measure the speed of sound in air using a variable length column of air.
Apparatus:
resonance-tube apparatus (an open ended tube which can be moved in and out of a container of water) constant frequency source (tuning fork or computer generated tone) rubber hammer meter stick rubber stopper
Procedure:
1. Set Up the Experiment:
Place the open ended tube into the water, and verify that it can produce a resonance tube length within the limits set by your instructor.
Confirm that you can hear the sound produced by the constant frequency source. If using a tuning fork, place it as shown in the picture, with the tuning for directly over the tube but not so close that it can vibrate and damage the tube. If using a different sound source, adapt your instructions below to your situation.
2. Find the Resonance Condition:
Starting with a very short air tube length, strike the tuning fork, place it near the tube, and increase the air column listening for a length that has a louder than normal sound. Place your ear near the top of the tube but off to the side slightly.
(If you place your ear directly over the top of the tube, you will be able to hear the “sea shell” effect and your ear will tend to make the open end a partially closed end, which will affect your results.)
Continue striking the tuning fork and raising the tube slowly until a marked increase in sound intensity is heard. Continue to refine your location until you have located the point of maximum sound intensity. This is the resonance point.
Measure the distance from the top of the water to the top of the glass tube. This is the length of the resonance length and corresponds roughly to ¼ wavelength, as shown in the diagram. Other resonance conditions may be possible if your tuning fork is matched appropriately with the tube.
Measure the temperature of the room in 0C and the inside diameter of the resonance tube.
3.