A fairly efficient steam turbine engine fired by coal is used to drive an electric generator. The generator operates between 2100°C and 385°C.

(a) Determine the maximum possible efficiency of the engine.


Answer: 72.3 %


Formula:

e = 1 - (Tc / Th) = 1 - (Qc / Qh) = ( W / Qh)


Explanation: Unsure??


(b) The engine absorbs 1.15 105 J from the hot reservoir every second. If the actual efficiency of the engine is 40.3%, determine the mechanical power the engine delivers.


Answer: 46 kW


Explanation:

Energy absorbed by the engine (J) * actual efficiency of the engine (%) = mechanical power the engine delivers (kW)


How does 1 - (385/2100) = 72.3 % ?
What do I Plug in to make e = 72.3 %