Question

The 3rd harmonic frequency of a guitar string is 768 Hz.

a) Calculate its 1st harmonic (fundamental) frequency. (2 marks)

b) Calculate its 4th harmonic frequency. (2 marks)

Answer 1

a) We can find the frequency of the 1st harmonic from the formula:

$$f_3=nf_1,$$ $$f_1=\dfrac{f_3}{n}=\dfrac{768\ Hz}{3}=256\ Hz.$$

b) We can find the frequency of the 4st harmonic from the sane formula:

$$f_4=nf_1=4\cdot256\ Hz=1024\ Hz.$$