In: Physics
You have a column of air 1.2 m long. The hard bottom of the tube forces a node there and the open end at the top of the tube forces an antinode there. Sound waves from a 1024 Hz tuning fork are sent down the column. Compute the wavelengths and frequencies for the first three allowed harmonics within the column.
The pipe open at one end and close at other end is known as closed pipe.
If the waves with some frequency are sent through the closed pipe, the waves gets reflects from closed end. When the incident and reflected waves with same frequency and in opposite direction superimposed the stationary waves formed in the closed pipe.
Let, l be the length of pipe.
v be the velocity of sound.
The first harmonic will form only when there is a node at closed end and anti-node at open end of pipe.
Here, the length of pipe is equal to one fourth of the wavelength λ.
The fundamental frequency is v/4L and the higher frequencies are odd harmonics of the fundamental frequency, i.e. 3f:5f:7f,.........
f= fundamental frequency.