Organ pipes, open at one end, resonate best at their first resonant length. Two pipes have length 23.0 cm and 30.0 cm respectively.

What is the wavelength of the sound emitted by each pipe?
What are the respective frequencies if the speed of sound is 341 m/s?
What is the air temperature in this church?

I'm mot confused by the first question. Does it mean, that the sound will sound best at 1/4 of the pipe's length, or that the pipe has been made so that it's already a quarter of the sound's wavelength?

1 answer

The "first resonant wavelength" is four times the (open) tube length. That is supposedly the "best" sound that the pipe makes.

The pipe lengths therefore tell you the wavelengths. Divide the sound speed by the wavelength to get the frequencies.

The equation for sound speed vs temperature can be used to determine the temperature.