The efficiency of a Carnot heat engine with an exhaust temperature of 121°C and an efficiency of 13.4% requires the intake temperature to be calculated using the formula e=1-(Tc/Th). The correct approach involves converting the exhaust temperature to Kelvin, resulting in an intake temperature of approximately 412.723 K, or 139.723°C. The initial calculation was incorrect due to the use of the Celsius scale instead of the absolute temperature scale.
PREREQUISITESStudents studying thermodynamics, engineers working with heat engines, and anyone interested in understanding the efficiency of thermal systems.
lzh said:Homework Statement
The exhaust temperature of a Carnot heat engine is 121◦C. What is the intake temperature if the efficiency of the engine is 13.4 %? Answer in units of ◦C.
Homework Equations
e=1-(Tc/Th)
The Attempt at a Solution
This seems like just a plug and chug problem:
0.134=1-(121/Th)
Th=139.723 ◦C
However, this answer is wrong-according to my Quest web homework. Am I missing something here? Thanks