Answer:
The frequency of a string wave is 922.5 Hz
Step-by-step explanation:
Given;
length of the string, L = 0.65 m
initial speed of the string wave at n = 5, v₁ = 320 m/s
initial frequency of the wave speed, f₁ = 1230 Hz
final speed of the string wave at n = 5, v₂ = 240.0 m/s
final frequency of the wave speed, f₂ = ?
speed of wave is related to frequency of wave and wavelength by the following equation;
V = Fλ
If the wavelength is constant at n = 5, then

Therefore, the frequency of a string wave, if speed of 240.0 m/s is used is 922.5 Hz