Answer:
7.9Hz
Explanation:
Step one:
given data
We are told that the fourth harmonic is at 31.5 Hz
We know that harmonics are a multiple of the fundamental frequency, such that if the fundamental frequency is 25Hz, then the second harmonic is
2nd= 2*25= 50Hz
3rd= 3*25= 75Hz........and so on
Step two:
In this problem, we are told that the 4th harmonic is 31.5Hz, that is
4th= 4*f= 31.5
Divide both sides by 4 to get f
f= 31.5/4
f= 7.9 Hz
Hence the first/fundamental frequency is 7.9Hz
