Question
A string is 2.4 m long, and the speed of sound along this string is 450 m/s. Calculate the frequency of the wave that would produce a first harmonic. Assume the string has nodes at both ends.
What I've Tried
Ln=2.4m
v= 450 m/s
f=?
n=2
Ln=(4-1)/4 * Wavelength
Wavelength = 2.4m/0.75m
=3.2m
Wavelength=v/f
f=v/wavelength
f=450 m/s / 3.2m
=140 hz.
The answer is 94 hz
What I've Tried
Ln=2.4m
v= 450 m/s
f=?
n=2
Ln=(4-1)/4 * Wavelength
Wavelength = 2.4m/0.75m
=3.2m
Wavelength=v/f
f=v/wavelength
f=450 m/s / 3.2m
=140 hz.
The answer is 94 hz
Answers
Damon
well, if nodes at both ends then the wave is twice as long as the string, 4.8 meters (draw it with half a wave on the string and bulge in the middle)
how long does it take for 4/8 meters?
T = 4.8/450
so
f = 450/4.8 = 93.75 Hz which is 94 indeed
how long does it take for 4/8 meters?
T = 4.8/450
so
f = 450/4.8 = 93.75 Hz which is 94 indeed