An organ pipe open at both ends has geometrical length 0.98 m. The end correction at each open end is 1 cm. If the speed of sound is 340 m/s, and the fundamental frequency is N Hz, find N.
Physics · Wave Motion · Standing Sound Waves, Organ Pipes and Resonance Tubes
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Question

An organ pipe open at both ends has geometrical length 0.98 m. The end correction at each open end is 1 cm. If the speed of sound is 340 m/s, and the fundamental frequency is N Hz, find N.

G1 Physics · Accepted Answer

For an open pipe, there are two open ends. Effective length is Lₑ = L+2e. Substitute: L = 0.98 m, e = 0.01 m. Thus, Lₑ = 0.98+0.02 = 1.00 m. For the fundamental mode, f₁ = v/(2Lₑ) = 340/[2(1.00)] = 170 Hz. Hence, N = 170.