Afreshwater marsh is drained to the ocean through anautomatic
tide gate that is 4ft wide and 3ft high. the gate is heldby hinges
located along its top edge at a and bears on a sill at b. at a given
time, the water levels in the marsh and in the ocean are6ft and 9ft
respectively. determine the force exerted by the sillon the gate at
b and the hinge reaction at a.

On a average work day more than work place firs are reorted

The mass flow rate of the fluid remains constant in all steady flow process. 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?