Question

A light wave has a 670 nm wavelength in air. Its wavelength in a transparent solid is 420 nm.? What is the speed of light in this solid? What is the light's frequency in the solid? A light wave has a 670 nm wavelength in air. Its wavelength in a transparent solid is 420 nm.? What is the speed of light in this solid? What is the light's frequency in the solid? Answers as well as explanations would be greatly appreciated so that I can understand how to work the problem when I solve it later. Thanks! 1 following 1 answer 1 Report Abuse Are you sure you want to delete this answer? Yes No

Answer 1

The frequency of a beam of light does not change as it passes from a medium to another, only its wavelength and speed are affected. The experimental speed of light in air is:
3  * 10^8 m/s
Therefore, the frequency of this beam of light is:
v = fλ; where v is speed, f is frequency, and λ is the wavelength. The frequency thus is:
3×10⁸ / (670 × 10⁻⁹) = 4.48 × 10¹⁴ Hz
The frequency will remain the same in the solid medium
The speed will then become:
4.48 × 10¹⁴ × 420 × 10⁻⁹ = 1.88 × 10⁸ meters per second