Example $6\mathrm{.}4$

During steady$-$state operation, a gearbox receives $60kW$ through the input shaft and delivers power through the output shaft. For the gearbox as the system, the rate of energy transfer by convection is $(-1\mathrm{.}2kW.$ For the gearbox, evaluate the rate of entropy production $,$ in $k\frac{W}{K},$ for $($a$)$ the gearbox as the system and $($b$)$ an enlarged system consisting of the gearbox and enough of its surroundings that heat transfer occurs at the temperature of the surroundings away from the immediate vicinity of the gearbox, If $=293K.$