Blue Lake is 3500 m long and 2800 m wide. The average depth is 20 m. The lake is fed by a stream having an average flow rate of 6.9 m^3/s. The stream flows through agricultural land, and the average concentration of the herbicide Kill-all in the stream is 33.1 μg/L. Kill-all degrades biologically with a rate constant of 0.18/ day.
Assuming that the lake is at steady-state conditions and completely mixed, what would be the Kill-all concentration in the lake under these conditions?

Oxygen at 300 kpa and 400 k is in a closed system with an initial volume of 0.1 m3. is now compressed in a polytropic process, with exponent of n 1.2, to a temperature of 500 k. calculate: a) the boundary work done during the compression, in kj b) the heat transfer during the compression, in kj

An air-conditioning system consists of a heating section and an evaporative cooler. air enters the heating section at 10°c and 70 percent relative humidity at a rate of 30m^3/min, and it leaves the evaporative cooler at 20°c and 60 percent relatively humidity. if the air conditioning system operates at a total pressure of 98 kpa, determine (a) the temperature and relative humidity of the air when it leaves the heating section, (b) the rate of heat transfer in the heating section, and (c) the rate of water added to air in the evaporative cooler

An ideal vapour-compression heat pump cycle provides a heating rate of 12btu/s. the working fluid, refrigerant 134a, enters the compressor as a saturated vapor at 40 psi and exits the condenser as a saturated liquid at 160 psi. determine (a) the mass flow rate of the working fluid in lb/min (b) the compressor power in btu/min. (c) the coefficient of performance.