What is Heat: Definition and 1000 Discussions

In thermodynamics, heat is energy in transfer to or from a thermodynamic system, by mechanisms other than thermodynamic work or transfer of matter. The various mechanisms of energy transfer that define heat are stated in the next section of this article.
Like thermodynamic work, heat transfer is a process involving more than one system, not a property of any one system. In thermodynamics, energy transferred as heat contributes to change in the system's cardinal energy variable of state, for example its internal energy, or for example its enthalpy. This is to be distinguished from the ordinary language conception of heat as a property of an isolated system.
The quantity of energy transferred as heat in a process is the amount of transferred energy excluding any thermodynamic work that was done and any energy contained in matter transferred. For the precise definition of heat, it is necessary that it occur by a path that does not include transfer of matter.Though not immediately by the definition, but in special kinds of process, quantity of energy transferred as heat can be measured by its effect on the states of interacting bodies. For example, respectively in special circumstances, heat transfer can be measured by the amount of ice melted, or by change in temperature of a body in the surroundings of the system. Such methods are called calorimetry.
The conventional symbol used to represent the amount of heat transferred in a thermodynamic process is Q. As an amount of energy (being transferred), the SI unit of heat is the joule (J).

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  1. SchroedingersLion

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    Hi guys, I am currently working through a book about thermodynamics and statistical mechanics as I was not so great in these course during my undergrad studies. First question: The book introduces heat as the kind of energy that terminates the temperature of a system. In other words: Give heat...
  2. F

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  3. M1gu3l

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  4. evinda

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  5. Rahulx084

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  6. K

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  7. C

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  9. T

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  10. Gregs6799

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  11. B

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  12. C

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  13. C

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  14. S

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  15. G

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  16. J

    Simple reversed heat engine problem

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  17. TheSlovakEngineer

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  18. T

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  20. Y

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  22. C

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  23. TheExibo

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  25. R

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  26. F

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  28. T

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  30. J

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  31. J

    Does Heat Radiation Decrease the Number of Photons Over Time?

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  32. Ed Lenarduzzi

    Compressed air, heat and pressure?

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  33. Andres Padilla

    Why this special case occurs in an exchange of heat

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  34. Beanyboy

    Exploring the Relationship Between Color and Temperature in Thermal Measurements

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  35. M

    I What is the solution to the heat equation with a constant added?

    I have seen how to solve the heat equation: $$ \frac{ \partial^2 u(x,t) }{\partial x^2} = k^2 \frac{ \partial u(x,t) }{\partial t} $$ With boundary conditions. I use separation variables to find the result, but i don't know how to solve the equation plus a...
  36. Cassius1n

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  37. F

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  38. Krushnaraj Pandya

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  39. C

    Heat released during combustion at constant pressure vs volume

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  40. T

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  41. cosmik debris

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  42. K

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  43. K

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  44. EastWindBreaks

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  45. T

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  46. S

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  47. P

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  48. K

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  49. J

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  50. T

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