All of them have the same potential energy <span />
Two major characteristics that change when air is heated and cooled is the density and the direction of the air flow. They change the movement of the air by heated air rises and cooled air doesn't.
The conversion factor you use is 100 cm = 1 m.
You can divide 20 by 100 to get the answer.
20 cm/100 cm =.2 m
Hope this helped!