Which gas is the most abundant of the trace gases?

nitrogen
oxygen
argon
carbon dioxide

What term do psychologists use to designate our personal awareness of feelings, sensations, and thoughts?

Which of the following is an example of motion in two dimensions?

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.