How do we measure the thermal energy of an object?

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Discussion Overview

The discussion revolves around the measurement of thermal energy in objects, exploring the relationship between temperature, mass, and thermal energy. Participants examine how thermal energy can be quantified and the implications of specific heat capacities in different materials.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants propose that temperature measures the average internal kinetic energy of an object, but question how thermal energy is measured, especially for objects with different masses and volumes.
  • Others suggest that thermal energy can be measured by adding or removing a known amount of energy and observing the resulting temperature change.
  • There is mention of specific heat and its relevance, with some participants noting that the specific heat capacities of different materials, like marshmallows and lakes, may influence their thermal energy comparisons.
  • One participant argues that while the marshmallow may have a higher specific thermal energy, the lake possesses a much higher total thermal energy.
  • Another participant expresses uncertainty about the concept of specific thermal energy and highlights the high specific heat capacity of water and ice.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between temperature and thermal energy, as well as the definitions and implications of specific heat. The discussion remains unresolved with multiple competing perspectives on how to measure thermal energy.

Contextual Notes

Limitations include potential misunderstandings of specific thermal energy and the dependence on definitions of thermal energy and specific heat capacities. The discussion does not resolve the mathematical relationships involved.

Mr Davis 97
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I know that temperature is used to measure the average internal kinetic energy of an object, but how do we go about measuring thermal energy? It seems as though temperature could only compare the thermal energy of objects with the same mass and volume. But for objects with different mass and volume, this would not be the case. For example, a lake has a higher thermal energy than a roasting marshmallow, while the marshmallow as a higher temperature.
 
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Mr Davis 97 said:
I know that temperature is used to measure the average internal kinetic energy of an object
It is not, but the concepts are related.
You can measure it by adding or removing a well-known amount of energy, and measuring temperature before and after.
Mr Davis 97 said:
For example, a lake has a higher thermal energy than a roasting marshmallow, while the marshmallow as a higher temperature.
There is the concept of specific heat and similar concepts, "[something] per mass of the object" - marshmallow and the lake have comparable specific heat capacities, and maybe similar specific thermal energy as well.
 
mfb said:
It is not, but the concepts are related.
You can measure it by adding or removing a well-known amount of energy, and measuring temperature before and after.
There is the concept of specific heat and similar concepts, "[something] per mass of the object" - marshmallow and the lake have comparable specific heat capacities, and maybe similar specific thermal energy as well.

I'd say the roasting marshmallow has a much higher specific thermal energy, whereas the lake has a much higher total thermal energy. But maybe I am missing something.
 
Not sure about the specific thermal energy, water and ice have a large specific thermal heat capacity.

For the total energy, sure.
 

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