it is easy to understand how a hot-air balloon works.
airplanes are harder to understand.
A gas burner heats the air inside the balloon.
the hot air is lighter than the air outside,so the balloon rises.
when the burner is turned down, the air inside the balloon cools off.
then the balloon starts going down.
that is how a hot-air balloon works.
two men in france took the first hot-air balloon ride in 1783.