Agood rule of thumb in hazardous conditions is to?
a. speed up and get off the road quicker.
b. counter steer your way to your destination, so you maintain control.
c. have your hazard lights on, so vehicles on all sides can see you.
d. slow down and increase your following distance to five seconds or more.

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

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?