Heat Transfer clarification of a problem

[Abninfamy]

1. The problem statement, all variables and given/known data
We're currently studying steady state one dimensional conduction heat transfer. We've touched on some surface convection, resistances in layers and fins.

I don't think I'll have much issue with this problem once I find this out:

What is a thermal driving force?



http://i144.photobucket.com/albums/r188/abninfamy/Question_NEW.jpg

[Mapes]

What is a thermal driving force?

It's just a fancy way of saying there's a constant temperature difference between one end and the other (and in the other parts, between one side and the other).

[Abninfamy]

Thank you very much!