Understanding Work and Heat Transfer in Thermodynamics

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 2K views
DiamondV
Messages
103
Reaction score
0

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?

Homework Equations

The Attempt at a Solution

 
Physics news on Phys.org
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.

chet