A composite wall, made up of two materials. The temperatures on the left and right faces are maintained at constant values of 100 C and 70 C, respectively. The thermal conductivity of two materials are k1=0.4W/mm-C, k2=0.2W/ww-C, and the thickness of two materials t1 and t2 are both 15 mm. Find the temperature distributionin in the wall using a linear finite element for each of the two materials.