g A steel [E = 26800 ksi and α = 7.1 × 10-6/°F] rod containing a turnbuckle has its ends attached to rigid walls. During the summer when the temperature is 93°F, the turnbuckle is tightened to produce a stress in the rod of 4.3 ksi. Determine the stress σwinter in the rod when the temperature is 21°F.

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)?