Water wave traveling in a straight line on a lake is described by the equation y(x, t)=(2.75cm)cos(0.410rad/cmx+6.20rad /st) where y is the displacement perpendicular to the undisturbed surface of the lake.

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.