Use the direct method to derive the element equations for the one-dimensional steady-sta...

Use the direct method to derive the element equations for the one-dimensional steady-state conduction heat-transfer problem shown in Figure P13–17. The bar is insulated all around and has cross-sectional area A, length L, and thermal conductivity K_xx. Determine the relationship between nodal temperatures t₁ and t₂ (° F) and the thermal inputs F₁ and F₂ (in Btu). Use Fourier’s law of heat conduction for this case.