(a) Using the energy balance method, and a mesh size Az = Ay = A=0.01 m, find out the discretised equation for nodes 1, 3 and 4, and determine the

maximum allowable time step At for all the nodes. Please provide answers to 3d.p. [N.B. Determine the maximum allowable time steps for each node based upon the quarter geometry, assuming symmetry along the central x and y axes.] \text { For Node } 1: \Delta t_{n 1}