Consider steady two$-$dimensional heat transfer in a long solid body and $L=0\mathrm{.}3m$ whose cross section is given below. The temperatures at the selected nodes and the thermal conditions on the boundaries are as shown. The thermal conductivity of the body is $k=180\frac{W}{m}*C,$ and heat is generated in the body uniformly at a rate of $e^{}={10}^7\frac{W}{m^3}.$ Using the finite difference method, derive the equations for temperatures at nodes $1,2,3,$ and $4.$ The mesh size of $x=2y=10cm.$

Clearly explain your choices for equations and Variables and where they come from. Thank you.