- Apr 1, 2022
Thank you for your explanation!I think the answer should be C (no change in frequency, speed decreases)
The frequency of any wave never changes when it moves into a different medium. This is because the frequency is dependent only on the source of the wave. Another way of seeing this is that if the photon frequency changes (i'm switching to the "particle" view of light only to illustrate this point), then its energy has changed which would violate conservation of energy.
The only things that are allowed to change are the speed and the wavelength.
Since the wave is bending towards the normal, it must be moving into a more optically dense medium and therefore slowing down (Snell's Law). The wavelength decreases.