A chain drive is desired to couple a gear motor with an elevator. The 30-hp gear motor willoperate at 400 rpm and the elevator drive shaft must operate as close to 80 rpm as possible. Select an appropriate chain size, commercially available sprockets, and number of links fora chain. Also calculate the actual chain speed and the center distance. Target a chain speed of less than 1000 ft/min; a chain speed of 650 ft/min or less wouldbe ideal, as this requires only manual lubrication for smooth operation.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Starting wih an energy balance on a rectangular volume element, derive the one- dimensional transient heat conduction equation for a plane wall with constant thermal conductivity and no heat generation.

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)?