The lowest frequency in the audible range is 20 hz. what is the length of the shortest open-open tube needed to produce this frequency? l = mwhat is the length of the shortest open-closed tube needed to produce this frequency? l = m

1. 8.5 m

For an open-open tube, the frequency of the fundamental mode of vibration is given by

where

v is the speed of the sound wave

L is the length of the tube

In this problem, we have:

f = 20 Hz is the frequency of the fundamental mode

v = 340 m/s is the speed of sound in air

Re-arranging the equation, we find

2. 4.25 m

For an open-closed tube instead, the frequency of the fundamental mode of vibration is given by

where

v is the speed of the sound wave

L is the length of the tube

In this problem, we have:

f = 20 Hz is the frequency of the fundamental mode

v = 340 m/s is the speed of sound in air

Re-arranging the equation, we find