Water is released from a water tank through a pipe to the atmosphere. the pipe diameter is 8 mm and the length is 6 m. water temperature is 15°c. the resistance coefficient of the pipe f = 0.015 and the difference between the water surface and the pipe outlet is 3 m. determine the exit velocity of water and sketch the hydraulic grade line (hgl) and energy grade line (egl) along the pipe. assume that minor loss can be ignore but not the major loss.

The temperature of air decreases as it is compressed by an adiabatic compressor. 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?

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody