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.