(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A wire is conducting electricity, given values of :

R' = .4 ohms/m D = .002 m Tinf=300k Tsur=300k k=380W/m*C

emissivity = 1 h=10W/m^2*C Ts = Find this sigma=Stefan boltzmann

Plot the Temperature of the wire versus the current I for 0<I<10 amps.

2. Relevant equations

P = I^2*R' = q'

Convective heat = h(Ts-Tinf) + sigma(Ts^4-Tsur^4) = I^2*R' / pi*D = q'/pi*D = q''

3. The attempt at a solution

Ok So my attempt as essentially to break down the equation I have set to convective heat. After breaking things up and solving for Ts, I found :

"(I^2*R' / pi*D) + (h*Tinf) + (sigma*(Tsur)^4)" = Ts(h+sigma*(Ts)^3)

**Ill use " ..... " for the left hand side of the equation

So my attempt was to break into in to two equations:

"..." = Ts and Ts = Cubed Root ( ("..." - h)/sigma)

For some reason whenever I go to solve for Ts, I get pretty absurd numbers.

Using Kelvin I get 3932 K for I=0

I dont even think I can use celsius here because of the stefan boltzman constant (My equations are not temperature differences).

Where am I going wrong and is this approach even possible?

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# Homework Help: Heat and Mass Transfer - finding surface temp

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