## Speed of Light

$c=\lambda v$

Nikita Patra 3J
Posts: 50
Joined: Sat Jul 20, 2019 12:16 am

### Speed of Light

If light has different speeds depending on the medium it is in, does it change wavelength, frequency, or both?

Michelle Shin 4B
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

### Re: Speed of Light

The wavelength changes, but the frequency remains constant in order to conserve energy.

Frederick Keith_4C
Posts: 65
Joined: Thu Sep 26, 2019 12:19 am

### Re: Speed of Light

The speed of light can misleading because the value we use is light as observed in a vacuum (3.00 x 10^8 m/s), but the speed of light is not the same as it passes from medium to medium. When it enters a denser medium (from air to glass for example), the speed and wavelength of light decrease while frequency stays the same. All of this depends on the index of refraction, n, however.
Equation: n=c/v
Light slows down here because it runs into more particles and gets absorbed and then re-emitted within the denser medium.