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Speed Of Sound Resonance Tube Experiment

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Introduction to the Speed of Sound Resonance Tube Experiment

The speed of sound is one of the most important measures that have been recognized by physicist and throat it many things that we’re not now before where measured. The phenomenon of the reasons that occurs during the experiment is interference of two waves of the same frequency speed and phase, resulting in constructive interference that has the violation highest energy and the highest amplitude. The pressure disturbance that travel from one particle to another indicates to the velocity of sound.

Basically, a sound wave is a travelling disturbance. Wave pulse indicates to a single disturbance while wave train is the series of disturbances. Wave frequency measures the number of pulse have been made in a length of given time. In the simplest sense, frequency is the number of vibrations per seconds. It is usually measured in Hertz(Hz). On the other hand, resonance is the natural vibration frequency of an object.

In the experiment, three activities have been done in order to exemplify the different properties of sound.

Aim Of The Resonance Tube Experiment

Aim of the speed of sound resonance tube experiment: measuring the speed of sound from stationary longitudinal waves in a closed air column.

Tools Of The Resonance Tube Experiment

·Closed resonance tube of variable length about 1 m long and 3-4 cm in diameter.

·Meter scale.

·Audio-frequency signal generator and loudspeaker or set of tuning forks of frequencies 512-256 Hz.

Closed resonance tube
Variable length, about 1 m long and 3–4 cm in diameter.
Meter scale
Used to measure air-column length in the tube.
Signal source
Audio-frequency signal generator and loudspeaker, or a set of tuning forks (256–512 Hz).

Steps And Method Of The Resonance Tube Experiment

Follow these steps to carry out the speed of sound resonance tube experiment and record accurate readings at each resonance position.

Using two positions of resonance for each frequency

Begin the experiment with the length of the air column in the resonance tube only a few cm in length.

Select a frequency of 500 Hz, adjust the volume control to a low but audible value and clamp the loudspeaker a few cm above the mouth of the tube. (Alternatively, select the fork of highest frequency, strike it smartly on a rubber pad and hold it over the mouth of the tube.)

Adjust the length of the resonance column until the tube responds to the imposed vibrations, i.e. until resonance occurs. By further small adjustments obtain the position of maximum loudness as exactly as you can. 

Measure the length of the air in the tube, repeat the measurement two or three times and take the mean, Now find a second and different position of resonance using the same frequency (or fork), but with about three times the length of air and again take the mean 12 of several readings of the length when resonance Occurs.

Obtain different values of 1, and 1, using other frequencies (or forks).

Parameters, Theory And Final Law of The experiment

Steps and Method

1

Using two positions of resonance for each frequency, begin the experiment with the length of the air column in the resonance tube only a few cm in length.

2

Select a frequency of 500 Hz, adjust the volume to a comfortable level, and slowly raise the water level in the tube until you hear the first position of maximum resonance (loudest sound). Record this air-column length as l₁. Continue raising the water level until you hear the second resonance point, and record this length as l₂. Repeat for a second frequency, such as 256 Hz, to obtain a second data pair.

Parameters, Theory & Final Law

c
Speed of sound
m/s
f
Frequency
Hz
l1
Air-column length, first resonance
m
l2
Air-column length, second resonance
m
ε
End correction
m
l1 + ε = 14 λ
l2 + ε = 34 λ
l2l1 = λ2 = c2f
c = 2f(l2l1)
ε = 12 (l2 − 3l1)

l₁ / m 1/f / s Q N P
Slope = PNQN = numerical value of c4
c = 4 × PNQN ms⁻¹
Final Law
c = 2f(l2l1)

Table Of The Resonance Tube Experiment

Table of readings for the speed of sound resonance tube experiment.

Frequency
f/Hz
First Resonance Position
Length of Air Column
l1/m
Second Resonance Position
Length of Air Column
l2/m
Speed of sound
c/m s⁻¹
End Correction
ε/m
(1)(2)(3)Mean (1)(2)(3)Mean
From c = 2f(l2 − l1)
From ε = 12 (l2 − 3l1)
Mean ………… …………
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Medical Application Of The Resonance Tube Experiment

Understanding the principles behind the speed of sound resonance tube experiment has direct clinical relevance in the following areas:

1. The intensity of ultrasound used for medical diagnostic is kept low to avoid tissue damage. Intensities of about 10-2W/m2 are used and seem to cause no ill effects
2. Ultrasound of considerably higher intensity is used for therapeutic purposes. Ultrasound diathermy is deep heating using ultrasound of intensities 1-10W/m2 .
3. Ultrasonic sound waves sent into the body are Doppler shifted by any motion in the objects that reflect them. It is possible, for example, to measure blood velocity by observing the Doppler shift of ultrasound reflected from the blood cells. More commonly, the Doppler shift of ultrasound is used to monitor the fatal heart motion.

4. The ultrasound used for sterilization because it kills the virus and bacteria.
5. It is also used as massage tool for muscles: cure the cancer, destruction the kidney stone.
6. Many devices use ultra-sonic sound, like toothbrushes.
7. Sonic denture cleaner or sonic cleaning device eliminates limescale deposits.
8. Ultra Max Cube: multiple of uses such as cleaning brushes, dentures, burs, diamonds, etc.

Frequently Asked Questions About Resonance Tube Experiment

Why do you measure two resonance positions instead of one?

Using two resonance positions lets you cancel out the end correction (ε), an offset caused by the antinode forming slightly outside the tube's open end. Subtracting the two lengths gives an accurate half-wavelength without needing to know ε in advance.

What determines the resonance length in the tube?

Resonance occurs when the length of the air column matches an odd multiple of a quarter wavelength of the sound wave. At these specific lengths, the reflected and incident sound waves reinforce each other, producing maximum loudness.

Why does frequency affect the resonance positions?

Higher frequencies have shorter wavelengths, so resonance occurs at shorter air-column lengths. Testing multiple frequencies and plotting the results lets you calculate the speed of sound from the slope of the line, rather than relying on a single measurement.