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human
[A:TLA] During Aang's fight with Firelord Ozai, after he unlocks the Avatar state, how fast is his "wind"?

Merry Christmas, all!  So I was re-watching Aang's fight with Firelord Ozai, and after he achieves the Avatar state, his gusts of wind easily crumbled a giant pillar of stone.  So I got to wondering, how fast would wind have to be moving to destroy solid stone that easily?
gpt
It wasn't the speed but the density of the air. Ang was able to compress the air into a form "solid" enough to impart a huge amount of kinetic energy. Speed alone doesn't do much. It must be combined with air pressure/density and debris to do much damage. 

Edit: Here is an example for you. Lets say the Avatar or any other Air Bender is placed inside an Air Tunnel/Funnel with a giant stone column. If they increase the speed of the air gradually they will not damage the stone. They may erode it over time but it wont destroy it or cause it to crumble. 

However if they cause a sudden gust of wind that will cause the air in front of it to compress first. The air between the stone and the gust compresses which increases the pressure on the stone. We must also consider that air benders can make the air they control feel almost solid, so it's not flowing around the column, but passing all of its energy directly into it, shattering it.