A gearbox operating at steady state receives 2 hp along the input shaft and delivers 1.89 hp along the output shaft. The outer surface of the gearbox is at 110°F. For the gearbox,
(a) Determine, in Btu/s, the rate of heat transfer and
(b) Perform a full exergy accounting, in Btu/s, of the input W = -0.225 W Ceramic substrate power. Let T0 5 70°F.