The Speed of Sound
The speed of sound is calculated using the formula:
velocity = frequency x wavelength
or
v = f x λ
Note: In physics the velocity is the speed of an object in a straight line.
Video of speed of sound experiment.
Experimental Theory
Frequency
The frequency is engraved on the tuning fork. eg.
E 329.6 Hz
A 440 Hz
C 523.3 Hz
Wavelength
The resonance wavelength is one quarter of a wavelength.
Now since the air molecules vibrate most rapidly just over the cylinder a correction factor is included.
The correction factor is 0.3 times the diameter of the cylinder.
The wavelength is 4(l + 0.3d)
Speed of sound
The formula for the spped of sound is
velocity = frequency x wavelength
v = f x λ
Substituting 4(l + 0.3d) for wavelength(λ), the formula for the experiment becomes
v = f x 4( l+ 0.3d)
or
v = 4f( l+ 0.3d)
where v = velocity or speed of sound, f = frequency of the tuning fork, l = length of the vibrating cylinder from the top to the water level and d = diameter of the cylinder
Speed of sound calculator
The speed of sound calculator is designed for this experiment. Enter the numeric values for the
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The speed of sound in dry air at 20°C (68°F) is 343.2 m/s