An air-filled pipe is found to have successive harmonics at 435 hz , 725 hz , and 1015 hz . it is unknown whether harmonics below 435 hz and above 1015 hz exist in the pipe. what is the length of the pipe?

L = 1.706 m

Explanation:

Three successive harmonics in the pipe is given as

now if we take the ratio of all frequency

then we have

f1 : f2 : f3 = 435 : 725 : 1015 = 3 : 5 : 7

since the ratio of consecutive frequency is in ratio of odd numbers so this must be 3rd harmonics, 5th harmonics and 7 harmonics

And as per the formula we have

i think the answer is a, hope this : )