In a factory, a large sheet of plastic (k=1.94 kcal/h.m.C), 12 mm in thickness, must be glued to a sheet of cork (k=0.035 kcal/h.m.C) of 25 mm of thickness. To obtain a ligature, the glue must be kept at 50 C for a considerable period of time. This is achieved by uniformly applying a heat flux over the plastic surface. The cork side, exposed to ambient air at 20C, has a film coefficient of 10 kcal/h.m.C. Neglect the thermal resistance of the glue. Calculate: a) The heat rate per m applied to obtain the temperature at the glue interface; b) temperatures on the external surfaces of plastic and cork.