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sfdrew
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Homework Statement
A 4.0g string of 0.67m length is vibrating at 300Hz in the third harmonic. The speed of sound in the air is 344 m/s. What is the tension in the string in SI units.
A) 110
B) 88
C) 69
D) 130
E) 150
Homework Equations
//frequency is equal to velocity over wavelength
f = v/lambda
The Attempt at a Solution
So, f sub n = nf sub 1, the fundamental frequency. That means that I can rewrite this using the frequency equation as...
100*2*L*sqrt(m/L) = sqrt(T)
=> 100*2*0.67*.0773 = sqrt(T)
=> 10.35 = sqrt(T)
=> (10.35)^2 = T
=> T = 107.2
107.2 is closest to 110, which is choice A, but it isn't exact and I didn't use the speed of sound in the air quantity for anything. I'm not sure if I did this problem correctly or not? Can anybody help?
Thanks in advance.
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