If the total energy change of an system during a process is 15.5 kj, its change in kinetic energy is -3.5 kj, and its potential energy is unchanged, calculate its change in specificinternal energy if its mass is 5.4 kg. report your answer in kj/kg to one decimal place.

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

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?