Understanding Work and Heat Transfer in Thermodynamics

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Work and heat transfer are distinct processes in thermodynamics. Work involves energy transfer through a force acting on an object, while heat transfer occurs at the molecular level through kinetic energy interactions. In the example of a hot metal dropped into room temperature water, heat flows from the metal to the water without work being done, as it is driven by temperature differences rather than external forces. This molecular interaction leads to a decrease in kinetic energy of the hot metal's molecules and an increase in the water's molecules. Thus, heat transfer does not require work in the traditional sense.
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Homework Statement


My lecture notes says that Work is the transfer of energy by means of a force acting on an object/body. What about heat energy? Does work also need to be done to transfer heat energy from hot object to cold object? Say if i drop a hot metal into room temp water. The metal gets colder and heat energy is transferred from metal to water which gets warmer. Does the metal do work on the water to transfer the heat energy?

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No, different forms of energy get transferred in different ways.
 
In the example that you gave, the transfer of heat is occurring on the molecular scale, by molecules with higher kinetic energy interacting with molecules with lower kinetic energy, so that the kinetic energy of the faster molecules decreases and the kinetic energy of the slower molecules increases. So it is not the same thing as work (which typically occurs macroscopically), and is typically the result of externally applied force.

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