ANSWER
3.28 m
Step-by-step explanation
The length of the string and the wavelength when the string is vibrating as its nth harmonic is related by,
In this problem, we are given the length of the string L = 8.2 m and we have to find the wavelength for this wave when the string is vibrating as the 5th harmonic,
Solving for the wavelength λ,
The wavelength of this wave is 3.28 m.