Hello, Plz Help Which conditions are necessary for rain to form? The temperature of the air below the cloud is above freezing.
The temperature of the air below the cloud is below freezing.
The sky has no clouds, and the temperature of the air is cold.
There is a warm layer of air and a cold layer of air closer to the ground.

Which changes of state do the labels represent? a: b: c:

The air that we breath is made mostly of which gaseous molecule

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.