In a resonance column experiment, a tuning fork of frequency 400 Hz is used. The first resonance is observed when the air column has a length of 20.0 cm and the second resonance is observed when the air column has a length of 62.0 cm. (a) Find the speed of sound in air. (b) How much distance above the open end does the pressure node form?
Given:
Length of air column at first resonance L1 = 20 cm = 0.2 m
Length of air column at second resonance L2 = 62 cm = 0.62 m
Frequency of tuning fork
(a) We know that:
Where, v is the speed of the sound in air.
So,
Therefore, the speed of the sound in air is 336 m/s.
(b) Distance of open node is d:
Therefore, the required distance is 1 cm.