Radiometric dating of a sedimentary rock sample shows an age of 1.5 million years. what conclusions can be drawn from this data? the rock is a minimum of 1.5 million years old but it may be older. radiometric dating cannot be used on sedimentary rock so no conclusions can be drawn. the rock is a maximum of 1.5 million years old but it may be younger. the rock is exactly 1.5 million years old.

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?