Velocity speed vs light

[CATSandKILOS]

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I am getting myself mixed up on the velocity of speed vs light in a medium.

From EK on light in a medium:

From EK on sound in a medium:

So for light entering a medium: a higher 👎 will move slower and only wavelength changes?
Then for sound in a medium: velocity is based on the medium and wavelength and frequency doesn't change?

How come wavelength changes for light in a medium and not speed? Am I missing something?

 

[Dr. Doctor]

The wavelength will change for both sound and light as they enter a different medium because they are both waves and will act in a similar manner when the are refracted. I think what has you confused is the fact that the passage excerpts are talking about two different things. The first one is discussing light entering a new medium (refraction) and the second one is discussing sound speed maintaing a constant velocity in one medium (no refraction is occurring). What the second excerpt is trying to show is that you can have different sounds with different wavelengths (1st harmonic 2nd harmonic etc) but they all have the same speed in a medium. Kind of like how different colours like red and violet travel at the same speed in the atmosphere but have different wavelengths 720nm vs 420nm.

 

[CATSandKILOS]

@Dr. Doctor Ohhh!! Thanks a bunch!