A harmonic wave is traveling along a rope. It is observed that the oscillator that generates the wave completes 40.0 vibrations in 30.0 s. Also, a given maximum travels 425 cm along the rope in 10.0 s. What is the wavelength?

Answer 1

The wave speed is
V = (425 cm)/(10 s) = 4.25 cm/s

The frequency is
f = 40/30 = 1.333 cycles per second

The wavelength is the wave speed divided by the frequency.

Answer 2

Drwls is incorrect as 425/10 is 42.5 NOT 4.25!
Also the measure for wave speed MUST be in m/s. Other than that it is correct.