Answer:
v = 8.0 m/s
Explanation:
The diagram clearly shows that the string is vibrating in the 5th harmonic. Hence, the length of string in terms o wavelength can be given as:
[tex]L = \frac{5}{2}\lambda\\\\\lambda = \frac{2}{5} L[/tex]
where,
λ = wavelength = ?
L = Length of string = 1 m
Therefore,
[tex]\lambda = \frac{2}{5}(1\ m)\\\\\lambda = 0.4\ m[/tex]
Now, the speed of the wave can be given by the following formula:
[tex]v = f\lambda\\[/tex]
where,
v = speed of wave =?
f = frequency of wave = 20 Hz
Therefore,
[tex]v = (20\ Hz)(0.4\ m)\\v = 8\ m/s\\[/tex]
Hence, the correct answer is:
v = 8.0 m/s
