Difficult Separable Integration Problem

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Homework Help Overview

The discussion revolves around a separable integration problem involving a differential equation that relates heat transfer (Q) to temperature (T) and position (x). The equation includes a function K(T) and constants related to the physical setup, with specified boundaries for T and x.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the manipulation of the equation to separate variables for integration. There are attempts to clarify the role of the terms in the equation and whether certain terms can be ignored. Questions arise about the existence of a function T(x) and the implications of its absence on the differential equation.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the equation and its components. Some guidance has been offered regarding the treatment of terms in the equation, but there is no explicit consensus on the correct approach to take.

Contextual Notes

Participants note potential issues with the formulation of the problem, including the presence of multiple dx terms and the necessity of defining T as a function of x. There is also mention of the boundaries for integration and the implications of the problem's setup on the solution process.

argpirate
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Homework Statement


Q=-1*K(T)*(H*W)*(dT/dx)+((I^2)(p)(dx)/(H*W))

K(T)=(197.29-.06333333(T+273))
H=0.01905
W=0.06604
I=700
p=10*10^-6
Q=some constant

Please separate and differentiate to solve for Q using variables of T and x.

Boundaries:
T: Upper=T1 (constant)
Lower=T0 (constant)

x: Upper=L (constant)
Lower=0 (obv. constant)

Homework Equations


a=dT/dx ----> a*dx=dT ----> integrate ax|=T|

The Attempt at a Solution



I plugged in all the values and tried to make common denominator to move dx to the Q side. But I could never get around getting rid of the dx in the numerator on the right side of the plus symbol in the original equation. Also, i wasnt sure whether to double integrate with boundaries for both integrals (was sort of weird)... Please help. Been working on this for a long time and can't figure out a way to manipulate it. Main issue is the two dx's and only one dT, so straight up integration won't work bc you would be integrating a dx when there is no dT left.[/B]
 
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Let me see if I get this right, your equation looks like ##Q=c_1K(T)\frac{dT}{dx}+c_2dx## where ##c_1,c_2## constants right? If yes , then you can ignore the ##c_2dx## term like it doesn't exist.

The reason is that if you take the ##\lim_{dx\rightarrow 0}## in both sides of the equation you ll end up with an equation that will be

##Q=c_1K(T(x))T'(x)## which is fairly easy to solve.
 
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Where do you see somewhere where T(x). There is no function for that. Can only use the information given.
 
argpirate said:
Where do you see somewhere where T(x). There is no function for that. Can only use the information given.
It has to be a function of x, otherwise ##\frac{dT}{dx}## is zero hence the whole equation is Q=0.
 
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Okay thanks. I finished this problem before I posted it on here. I was just looking for a method that involved separation and integration. In my original solution (which was successful), I had to make a T(x) equation. I was trying to look for a method that didn't involve this.
 
argpirate said:
Q=-1*K(T)*(H*W)*(dT/dx)+((I^2)(p)(dx)/(H*W))
Is that a correct statement of the problem as given to you? That isolated dx makes looks wrong, and I don't see where "separable integration" comes in. If you mean separation of variables, that is usually in the context of a differential equation involving one dependent variable and two or more independent. Delta2 proposes to ignore the dx, but I suspect a typo.
 

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