text: To have resonance, the sound wave must complete a whole number of cycles when travelling through the pipe. \n\nFor instance, sound travels 340 meters in one second. If you had an organ pipe 340 meters long, sound with a frequency of 1 Hz would resonate the pipe because it completes exactly 1 cycle in 1 second, which is how long it takes the sound to travel 340 meters.\n\nFirst find how long it will take the sound to travel through the pipe:\n\nl / v = t\nWhere l is the length of the pipe and v is the speed of sound.\n\nNext, find the frequency that would allow just one full cycle to be completed while in the pipe:\n\nt * f = r\nWhere t is the time sound takes to travel through the pipe, f is the frequency with which the pipe will resonate, and r is the number of cycles the sound wave will complete. To obtain the frequency f, set r=1 and solve.\n\nBelow is the problem solved:\nt = l / v = 2 / 340 = 1/170 s\nf = r / t = 1 / (1/170) = 170 Hz\n\nI hope this helps!