A cylindrical metal tube has a length of 50 cm and is open at both ends. Find the frequencies between 1000 Hz and 2000 Hz at which the air column in the tube can resonate. Speed of sound in air is 340 m s-1.
Given:
Length of cylindrical metal tube L = 50 cm
Speed of sound in air v = 340 m/sec
Fundamental frequency 
of an open organ pipe:
So, the required harmonics will be in the range of 1000 Hz to 2000 Hz.
=2×340=680 Hz
=3×340=1020 Hz
=4×340=1360 Hz
=5×340=1700 Hz
=6×340=2040 Hz
f2, f3, f4… are the second, third, fourth overtone, and so on.
The possible frequencies between 1000 Hz and 2000 Hz are 1020 Hz, 1360 Hz and 1700 Hz.
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