A closed pipe is suddenly opened and changed to an open pipe of same length. The fundamental frequency of the resulting open pipe is less than that of 3rd harmonic of the earlier closed pipe by 55 Hz. Then the value of fundamental frequency of the closed pipe is
Frequency of first mode of vibration
n1=3v4l⟶(1) (closed pipe)
and frequency of first mode of vibration
n2=v2l⟶(2)(open pipe)
According to question,
n1−n2=3v4l−v2l=55or,3v−2v4l=55∴v4l=55Hz
Which is fundamental frequency of the closed pipe