Chapter 4, Problem 4.42P

Determine expressions for $q_{\left(m-1,n\right)\to \left(m,n\right)},q_{\left(m+1,n\right)\to \left(m,n\right)},q_{\left(m,n+1\right)\to \left(m,n\right)}$ and $q_{\left(m,n-1\right)\to \left(m,n\right)}$ for conduction associatedwith a control volume that spans two different materials.There is no contact resistance at the interface between thematerials. The control volumes are L units long into thepage. Write the finite difference equation under steadystateconditions for node $\left(m,n\right).$