Heat radiated from within a shell

Thread starter sparkle123
Start date Mar 15, 2012
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Heat Shell

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The discussion clarifies that ΔQ/Δt, representing the rate of heat transfer through a sphere of radius r, does not equal the total power P generated within the entire planet. Instead, in a steady state, ΔQ/Δt should correspond to the power generated within the smaller sphere of radius r. This distinction is crucial for understanding heat transfer dynamics. The conversation emphasizes the importance of defining the system boundaries when analyzing heat flow. Overall, accurate calculations depend on recognizing the difference between localized and total power generation.

Mar 15, 2012

sparkle123

Why isn't ΔQ/Δt just P?

Thank you!

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Mar 18, 2012

Redbelly98

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In this problem, P is the total power generated within the entire planet. ΔQ/Δt is the rate of heat transfer through the surface of a sphere of radius r<R. In steady state, ΔQ/Δt must equal the power generated within a sphere of radius r, not within the entire planet.

Mar 18, 2012

sparkle123

Thanks! :)

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