For a heat engine to work, it must operate in cycles.
Firstly, heat is added into the system. Let the heat added into the system be represented by [Qh]. After that process, some of the energy that were added into the system will be used to do work e.g the materials expanding or increasing in temperature
Let the work done be [W]. After that, the rest of the heat will then be removed at a cold temperature.
Let the heat removed be represented by [Qc]. If we apply the law of Conservation of Energy, we will be able to form the equation: …show more content…
The second law of thermodynamics states that even under ideal conditions, no heat engine can convert all the energy it receives to do useful work, some energy will be lost, and each time a system goes through a thermodynamic process, the system can never completely return to exactly the same state it was before (irreversibility). For example, if a hot object is placed next to a cold object, the cold object will become warmer and the hot object will be cooler until a thermal equilibrium is reached. However, heat will still be lost to the surroundings. It is common knowledge that heat, of its own volition, does not transfer from a cold medium to a warmer medium. It is therefore impossible to construct a refrigerator that operates without an input of work. So for a refrigerator to work it requires an input of energy, Win.
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