ANSWER
[tex]3)1320Hz[/tex]EXPLANATION
To find the frequency of the third harmonic for an open-ended pipe, we apply the formula for the frequency of harmonics for open-ended pipes:
[tex]f=nf_o[/tex]where fo = fundamental frequency; n = nth harmonic
Therefore, the frequency of the third harmonic is:
[tex]\begin{gathered} f=3\cdot440 \\ f=1320Hz \end{gathered}[/tex]The answer is the 3rd option.
