Amass of air occupying a volume of 0.15m^3 at 3.5 bar and 150 °c is allowed to expand isentropically to 1.05 bar. its enthalpy is then raised by 52kj (note the unit) by heating at constant pressure. assuming that all processes occur reversibly, sketch them on a p-v chart and calculate the total work done and the total heat transfer.

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)?