What’s the doing between high and low pressure systems.

High pressure systems entail sinking air, while lows entail rising air. High pressure systems form where air converges in the higher levels of the atmosphere. The converging air has nowhere to go and is forced to sink toward the ground. This sinking effect inhibits cloud formation and therefore precipitation.

c)as speed changes, wavelength and frequency change.

everything changes!

not too sure thinking all accelerations are pointed down