The third harmonic of a tube closed at one end is 735 Hz.If the speed of sound in air is 335 m/s,the length of the tube must be
A)11.6 cm
B)22.9 cm
C)34.1 cm
D)45.7 cm
E)57.3 cm

Question

Quizplus · Accepted Answer

For a tube closed at one end, the frequency of the nth harmonic is given by:
f_n = n*v/(4*L)
where v is the speed of sound and L is the length of the tube.

For the third harmonic, n = 3 and f_3 = 735 Hz. Substituting these values and solving for L:
L = n*v/(4*f_n)
L = 3*335/(4*735)
L = 34.1 cm

Therefore, the correct answer is option C, 34.1 cm.

The Third Harmonic of a Tube Closed at One End