Rate of Energy Transferred, Aluminum Pot

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Homework Help Overview

The problem involves calculating the rate of energy transfer through the bottom of a circular aluminum pot, given specific dimensions and temperature differences. The subject area pertains to thermal conductivity and heat transfer principles.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the appropriateness of the equation for heat transfer, questioning the values for area and thickness used in the calculations. There is also a focus on the accuracy of the thermal conductivity constant provided by the original poster.

Discussion Status

Some participants have confirmed the use of the correct equation and parameters, while others express concern over the reliability of the constants used. There appears to be a divergence in the results obtained, prompting further exploration of the assumptions made.

Contextual Notes

There are indications that the original poster may be using questionable sources for constants, which could affect the calculations. The discussion reflects uncertainty regarding the validity of these sources and their impact on the problem-solving process.

DracoMalfoy
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Homework Statement


The bottom of a circular, aluminum pot has a radius of 8cm and a thickness of 1cm. The temperature of the stove top is 120 degrees celsius and the temperature of the pot initially is 20 degrees celsius. What is the rate at which energy is transferred through the bottom of the pot?

a. 300W

b. 2589W

c. 2.67X10^5W

d. 4.79X10^4W

e. 7.89W

Homework Equations



P=KA(TH-TC)/L

The Attempt at a Solution


[/B]
Thermal Conductivity(K) of Aluminum: 220 k (J/s⋅m⋅ºC)
A(Cross sectional area the energy goes through): .08m??
(Th-Tc): (120-20degreeC)
L(Distance energy travels): .01m?

Im not sure if this is the right equation to use, or if A or L is correct. I am not getting the answer this way.
 
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DracoMalfoy said:
if this is the right equation to use, or if A or L is correct
Right equation, right L, but the 8cm is a radius, not an area.
 
haruspex said:
Right equation, right L, but the 8cm is a radius, not an area.
i understand. i got the answer. d i think
 
DracoMalfoy said:
i understand. i got the answer. d i think
Yes, that's the nearest to what I get ... 44230W ... but worryingly different.
 
haruspex said:
Yes, that's the nearest to what I get ... 44230W ... but worryingly different.
I've noticed that the OP has several posts where the source of relevant constants is a tad dubious and differ from other more reliable sources by a fairly substantial percent. I'm not sure if these sources are mandated by the course or randomly chosen by the OP, but either way it's a bit disconcerting.
 
gneill said:
I've noticed that the OP has several posts where the source of relevant constants is a tad dubious and differ from other more reliable sources by a fairly substantial percent. I'm not sure if these sources are mandated by the course or randomly chosen by the OP, but either way it's a bit disconcerting.
I wondered about the conductivity figure, but if anything it seems a little high.
 

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