The thermostat in a house is set at 70°F. Consequently, the inside of the house is always at 70°F, regardless of the season.

A. One day, the outside temperature is 50°F, and the house loses 100 kJ of heat to the surroundings. What is the change of entropy for the universe resulting from this process?

B. Besides the heat transfer noted in part A, is there any other source of entropy generation associated with maintaining this house at 70°F?

C. If a Carnot engine were designed to operate with the house as the heat source and the outdoors as the heat sink, what would its efficiency be on this day? How much work would be produced if the 100 kJ was sent to this Carnot heat engine, rather than simply being lost to the outdoors?