Waves of all wavelengths travel at the same speed v on a given string. Traveling wave velocity and wavelength are related by v=lambda*f,where v is the wave speed, lambda is the wavelength (in meters), and f is the frequency [in hertz]. Since only certain wavelengths fit properly to form standing waves on a specific string, only certain frequencies will be represented in that string's standing wave series. The frequency of the nth pattern/harmonic is f_n = v/lambda_n = v/(2L/n) = n*v/{2L}. Note that the frequency of the fundamental is f_1 = v / (2L), so f_n can also be thought of as an integer multiple of f_1: f_n = n*f_1. Now, the question. Assume the frequency of the fundamental of the guitar string is 320 Hz. At what speed v do waves move along that string? Use the guitar's length from previous question.