A well on the side of the roas the kind with a buket attach

A well on the side of the roas ( the kind with a buket attached to a rope and water at the bottom) has a depth of 1.23 m ( measured from the upper rim to the surface of the water ). the temperature is 20C, and you just haen to have a set of tuning forks with you. Determine the lowest frequency tuning fork that will create first harmonic resnance ( or first position resonance) in the air column in the well. ( the speed of sound at 20C IN 343 m/s. ) is this frequency audible to humans

Solution

The well is act as organ pipe such that one end is closed and other is open.

Fundamental frequency (or first harmonic frequency)of such organ pipe f = v/4L

Where v = Speed of sound = 343 m/s

          L = depth = 1.23 m

Substitute values you get , f = (343)/(4 x1.23)

                                         = 69.71 Hz

The audible range of frequencies by humans is from 20 Hz to 20000 Hz

So, this frequency is audible to humans