An organ pipe has two successive harmonics with frequencies 1372 and 1764 hz. (a) is this an open or a stopped pipe? explain. (b) what two harmonics are these? (c) what is the length of the pipe? –

 a) a stopped pipe. We will divide the two successive harmonics with frequencies 1372/1764.
1372/1764 = 7/9 
which shows the nth harmonic is in odd multiple 
b) 7th harmonic and 9th harmonic 
c) 1372Hz = 7fo where fo = v / 4L 1372 = 7(330) / 4L solve for L, L =  0.4209 m  The length of the pope is 0.4209 meter.

Prepared to discuss your findings with your teacher or fellow students