QUESTION: Which scenario illustrates a tolerance stack in the part design?
POSSIBLE ANSWERS:
Operator inexperience with maintaining tool offsets allows the machining to vary widely from
the specifications set forth in a part blueprint, resulting in an unusable part.
Due to a damaged tool, the cutting of a metal part did not meet the tolerance specification set
forth in a blueprint, resulting in a scrapped part.
By chance, the machining of a part met the tolerance specifications set forth in a blueprint, but
a
the accumulation of variation from the upper or lower limits of the tolerance results in an unusable
part.

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 higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Calculate the bore of a cylinder that has a stroke of 18 inches and an extension time of 6 seconds at a flow rate of 4 gal/min.