For a bolted assembly with six bolts, the stiffness of each bolt is kb 5 3 mlbf/in and the stiffnessof the members is km 5 12 mlbf/in per bolt. an external load of 80 kips is applied to theentire joint. assume the load is equally distributed to all the bolts. it has been determined touse 12 in-13 unc grade 8 bolts with rolled threads. assume the bolts are preloaded to 75 percentof the proof load.(a) determine the yielding factor of safety.(b) determine the overload factor of safety.(c) determine the factor of safety based on joint separation

Fluids at rest possess no flow energy. 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?

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false