Select the correct answer. Alan is walking on a street and passes by a very busy construction site. He sees engineers hanging one end of various objects to the ceiling and
the other end to heavy weights. They observe the objects and then then take down notes. What are the engineers doing?
OA measuring the height of the ceiling
OB. performing tensile test
ОС. checking the strength of the ceiling
OD
measuring the weight of the object

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?

The drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion. a)-true b)-false

Hydraulic fluid with a sg. of 0.78 is flowing through a 1.5 in. i. d. pipe at 58 gal/min. the fluid has an absolute viscosity of 11.8 x 105 lbf-sec/ft2. is the flow laminar, turbulent or within the critical range? give both a numerical reynolds number and a term answer.