Final answer:
The wavelength of light in a certain medium can be found using the formula λn = λo/n, where λn is the wavelength in the medium, λo is the wavelength in vacuum, and n is the medium's index of refraction.
Step-by-step explanation:
The speed of light in a vacuum is a constant value of approximately 3.00 × 108 m/s. In a certain medium, the light with a vacuum wavelength of 506 nm travels at a speed of 1.27 × 108 m/s. To find the wavelength in the medium, we can use the formula: λn = λo/n, where λn is the wavelength in the medium, λo is the wavelength in vacuum, and n is the medium's index of refraction.
Plugging in the values, we get: λn = 506 nm / 1.27 × 108 m/s = 3.98 nm.