Tough Physics question please help!?

Question

The range of human hearing is roughly from twenty hertz to twenty kilohertz. Based on these limits and a value of 325 m/s for the speed of sound, what are the lengths of the longest and shortest pipes (open at both ends and producing sound at their fundamental frequencies) that you expect to find in a pipe organ?

A. shortest pipe ? m
B. longest pipe ? m

Answer 1

The pipe has to be 1/2 wavelength long. Wavelength, w is speed of sound, v, over frequency f

w = c/f so w = 16.25 m for f = 20 Hz and w = 0.01625 m for 20 kHz

Thus the pipe for 20 Hz is 8.125 m long (1/2 wavelength) and for 20 kHz it is 0.008125 m long