The figure shows a sandwich panel with an insulating core (Kins-0.5 W/m-K). The vertical steel plates are also supported with two identical thinner steel plates. The thermal conductivity of steel plates 15 W/m-K. The bottom side of the panel is exposed to a convection environment with a heat transfer coefficient of 200 W/m2 - K at the fluid temperature of 25 C. The top side is maintained at a constant surface temperature of 250 C. Neglecting the contact resistances and heat transfer in horizontal direction; 1) Draw a thermal resistance network that can be used to represent this situation and properly label all temperatures and resistances? 2) Calculate the heat transfer rate from top to bottom if the ths1= 5 cm, ths2= 20 cm, Ls1= 250 cm and Ls2= 2.5 cm? 3) Find the thermal conductivity of a new material that will give the equivalent heat transfer rate that you found in part b for the same volume of setup? ths1 Ls1 K th $2 To Kins Lins1 Ls2 T..h.. th1 K