An aluminum [e = 1 ksi] bar is bonded to a steel [e = 3 ksi] bar to form a composite beam. the aluminum bar has width b = 2.50 in. and height h1 = 0.625 in.
the steel bar has width b = 2.50 in. and height h2 = 0.875 in.
the composite beam is subjected to a bending moment of m = +300 lb-ft about the z axis.(a) the maximum bending stresses in the aluminum and steel bars.
(b) the stress in the two materials at the joint where they are bonded together.

What precautions should you take to prevent injuries when dealing with heavy loads?

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

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?