Question

If the seventh and fourth standing wave frequencies of a string differ by 144 Hz, what is the fundamental frequency of the string?

Answer 1

the fourth standing wave frequency is 4*f1, where f1 is the fundamental wave frequency. The seventy fundamental frequency is 7*f1

7*f1 - 4*f1 = 3*f1 = 144 hz

f1 = 144/3

Answer 2

This is not correct. The answer is simply as follows:

Let f* be the fundamental frequency.

Then f*[(1/4)-(1/7)]=144Hz.

f* = 1344 Hz