Question

in a resonance tube experiment, if the first and second resonance length are obtained as 36cm and 89cm respectively, when a turning fork of frequency 270Hz is used, calculate the velocity of sound in air.

Answer 1

The first resonance corresponds to to λ/4 , the second resonance corresponds to 3λ/4. So, we have

$$0.36=\frac{\lambda}{4}=\frac{c}{4f},\\\space\\ c=4f·0.36=367.2\text{ m/s}.$$