Thermal condution? little confusing can u to remove my doubt.

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Discussion Overview

The discussion revolves around the concept of thermal conduction, specifically the interpretation of the law of thermal conduction and the meaning of the term dQ/dt. Participants explore the behavior of a cylindrical object with one end heated and the other end at a lower temperature, raising questions about energy transfer and temperature equilibrium.

Discussion Character

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

Main Points Raised

  • One participant seeks clarification on the meaning of dQ/dt in the context of thermal conduction.
  • Another participant states that dQ/dt represents the rate of heat flow in the system.
  • A participant questions the symmetry of the cylindrical object, suggesting that it is unclear how one end could be considered hotter than the other.
  • Further elaboration is provided on a scenario involving a cylindrical metal rod, where one end is heated and the other is held in hand, raising questions about why the temperature at the hand-held end does not increase.
  • One participant proposes that the rate of cooling is proportional to temperature, suggesting that the rate of heating from the stove eventually equals the rate of cooling at the other end.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of the thermal conduction law and the behavior of temperature in the described scenario. The discussion remains unresolved regarding the underlying principles and assumptions related to dQ/dt and energy transfer.

Contextual Notes

There are limitations in the assumptions made about the system, particularly regarding the symmetry of the cylindrical object and the conditions under which heat transfer occurs. The discussion does not resolve the mathematical implications of dQ/dt.

vkash
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thermal condution? little confusing can u please help to remove my doubt.

According to law of thermal conduction dQ/dt=-kAdθ/x. variable have their usual meaning.
first of all i want to know what is meaning of dQ/dt in this law??

If we see it in a cylindrical object with it's curved part fully insulated. then one end will have higher temperature and other will have lower temperature So one end is getting more energy (which is more hot) but other end is cooler which means it radiate less energy so where does some energy goes?

I think i m wrong somewhere in understanding this law can u please help me in find out my error;
 
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\frac{dQ}{dt} is the rate of heat flow in the system.
Your second paragraph seems off to me since the cylinder has symmetry between the ends so how one end could be chosen over the other to be the hotter one is beyond me.
 


Still in doubt

If you doesn't understand second para then; think of this condition that there is a cylindrical metal rod of certain length you put one of it's end in a stove and other end in your hand; after a steady u will observe that temperature the end in ur hand is not increasing. why it stopped increasing.(Consider rod is insulated in curved region)
Temperature of rod end in your hand is lower than that of stove; It should same that of stove since the amount of heat enter in the from stove should equal to heat released from other end.
where my explanation is wrong. I think it depend on the more deeper meaning of dQ/dt ; that's why my first question is dQ/dt.
 


Ah now I understand the situation, the rate of cooling is proportional to the temperature so as the end gets up to a high enough temperature its rate of cooling becomes equal to the rate of heating coming from the stove.
 

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