Use the control-volume approach and derive the node equation for node (2, 2) in Figure and include a heat source at this point. Use the following values for the constants: Δz = 0.2.5 cm, h = 10 cm, kA = 0.25 W/cm · C, and kB = 0.45 W/cm · C. The heat source comes only from material A at the rate of = 6 W/cm3.