A copper alloy cylinder that is 1.3 feet long with a diameter of 45.27 inch is subjected to a tensile stress of 1,140 psi along its length. Assuming this applied stress is purely elastic, calculate the diameter, in inches, of the cylinder under this load. For this alloy, the elastic modulus is 904,672 psi and the Poisson's ratio is 0.33.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?