Final answer:
Shortwaves typically move faster than longwaves, but decelerate when they pass through a longwave ridge. In air, X's characteristics suggest it could be light waves, whereas Y could be sound waves due to the shorter wavelength and need for a medium.
Step-by-step explanation:
Atmospheric shortwaves usually move faster than longwaves and slow down when they move through a longwave ridge. Wave X and Y mentioned in the question could be types of electromagnetic radiation or mechanical waves. In air, if X travels much faster than Y and has a much shorter wavelength, X could represent electromagnetic waves like light waves, and Y could represent sound waves. Sound waves require a medium to travel and have shorter wavelengths than infrared radiation, which is a type of electromagnetic wave. Short, tight electromagnetic waves, which carry more energy, could be at the high-frequency and short-wavelength end of the spectrum, while long wavelength waves, like infrared, carry less energy.