A stream with cross section area of 12 m? carries 9 m%/s of
water with a caffeine
concentration of 17 mg/L at its
inlet. The rate of decay of
caffeine in the stream is 0.18
L/mg. day. What will be the
steady-state concentration of
caffeine in the stream
downstream at distance of 20
?Km kilometer from the inlet​

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?