B. A guitar string has a length of 0.90 m. When you pluck it, it plays a "C" that has a frequency of 256 Hz. How fast is the wave moving back and forth along the string? (Choose one of the equations from the box at the top of the page to solve this problem.)

Equations to use: v = λ ∙ f v=d/t

461 m/s

Explanation:

Given the string length of guitar, l = 0.90 m

Frequency, f = 256 Hz

Using frequency, wavelength and velocity relation as

v=f λ

Here λ is wavelength.

Now for guitar string the length must be equal to half of wavelength, so

λ = 2l

Therefor above formula becomes as

v = f*2l

Substituting the given values, we get

v = 256*2*0.90

v = 460.8 m/s = 461 m/s

Thus, the wave moving back and forth along the string with velocity 461 m/s.