8. What is the mass of an object if a force of 34 N produces an acceleration of 4 m/s/s? F = 34 N
F
34
m-
m-
m = 8.5 kg
a
4
a - 4 m/s

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.