A four-cylinder, four-stroke internal combustion engine operates at 2800 RPM. The processes within each cylinder are modeled on cold air-standard Otto cycle with a pressure of 14.7 lbf/in.2 , a temperature of 80oF, and a volume of 0.0196 ft3 at the beginning of compression. The compression ratio is 10, and maximum pressure in the cycle is 1080 lbf/in.2 Determine, using a cold air-standard analysis, the power developed by the engine, in horsepower, and the mean effective pressure, in lbf/in.2

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w