Consider a lake with volume v and constant inflow and outflow of water, q. a point source load, w, adds a contaminant, c, to the lake at a constant rate (i. e., w is constant). draw a conceptual model for this scenario, write the appropriate differential equation mass balance model, solve the model, and provide a qualitative sketch of c vs time. consider now a point source load that varies linearly with time such that w = at. draw a conceptual model for this scenario, write the appropriate differential equation mass balance model, solve the model, and provide a qualitative sketch of c vs time.

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?

Water in a partially filled large tank is to be supplied to the roof top, which is 8 m above the water level in the tank, through a 2.2-cm-internal-diameter pipe by maintaining a constant air pressure of 300 kpa (gage) in the tank. if the head loss in the piping is 2 m of water, determine the discharge rate of the supply of water to the roof top in liters per second.

Calculate the bore of a cylinder that has a stroke of 18 inches and an extension time of 6 seconds at a flow rate of 4 gal/min.