A heat engine takes in 840 kJ per cycle from a heat reservoir. which is not a possible value of the engine's heat output per cycle?
Hmmm. Are there choices listed?
A heat engine takes in 840 kJ per cycle from a heat reservoir. Which is not a possible value of the engine's heat output per cycle?
400 kJ
150 kJ
0 kJ
those are the answer choices
To determine which value is not possible for the engine's heat output per cycle, we need to apply the laws of thermodynamics.
The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system:
ΔU = Q - W
Where:
ΔU = Change in internal energy
Q = Heat added to the system
W = Work done by the system
In this case, the heat added to the system is 840 kJ per cycle from a heat reservoir. Assuming no work is done by the system (which is a common assumption for simple heat engines), we can determine the change in internal energy:
ΔU = Q - 0
ΔU = 840 kJ
Therefore, the change in internal energy during each cycle is 840 kJ.
Now, let's consider the possible values for the engine's heat output per cycle:
1. The heat output per cycle can be equal to the heat added per cycle (840 kJ). This occurs when all the heat absorbed by the engine is converted into work.
2. The heat output per cycle can be less than the heat added per cycle. This occurs when some of the heat absorbed by the engine is lost as waste heat and not converted into work.
3. The heat output per cycle cannot be greater than the heat added per cycle. This violates the conservation of energy.
Therefore, any value greater than 840 kJ per cycle is not possible for the engine's heat output.
In conclusion, the value that is NOT possible for the engine's heat output per cycle is any value greater than 840 kJ per cycle.