Systems tend to change until they reach equilibrium. based on this fact, what will happen when cold air and warm are added to the same container?
a.
the warm air will get cooler and the the cool air will get warmer.
b.
only the cold air will change temperature.
c.
the warm and cold air will stay apart from each other.
d.
the warm and cold air will both get cooler.

The answer is; A

When the two air masses are mixed, the molecules of the warm air have higher kinetic energy than those of the cool air. Therefore, the molecules of the warm air bombard those of the cool air and transfer some of their kinetic energy. The warm air will get cooler while the cool air will get warmer until equilibrium is reached.  

e/c, where e is its total energy