A standing wave with a fundamental frequency 1.25x10 2 Hz is set up on a string of length 0.750 meters. What is the frequency of the third harmonic?

500Hertz

Explanation:

Given the fundamental frequency of the string given as  1.25x10²Hz

Harmonics are integral multiples of the fundamental frequency.

In strings, the third harmonic F3 is expressed in terms of the fundamental frequency expressed as;

F3 = 4F0

F0 is the fundamental frequency;

Given

F0 = 1.25x10²Hz

F3 = 4(1.25x10²)

F3 = 4(125)

F3 = 500Hz

Hence the  frequency of the third harmonic is 500Hertz