Assuming the speed of sound is 340 m/s, what is the most likely speed of the jet shown below?

1.25 m

Explanation:

For an open-air pipe, the two ends of the pipe corresponds to two antinodes of the standing wave; therefore, the wavelength of the wave is equal to twice the length of the tube:

\lambda=2 Lλ=2L

We can rewrite the wavelength using the speed of the sound wave, v, and the frequency, f:

\lambda=\frac{v}{f}λ=

f

v

And substituting into the previous equation we get

\begin{gathered}\frac{v}{f}=2L\\L= \frac{v}{2f}\end{gathered}

f

v

=2L

L=

2f

v

And using

v = 340 m/s

f = 136 Hz

We find the length of the organ pipe:

L=\frac{340 m/s}{2(136 Hz)}=1.25 mL=

2(136Hz)

340m/s

=1.25m