Aheat-conducting rod, 0.90 m long and wrapped in insulation, is made of an aluminum section that is 0.20 m long and a copper section that is long. both sections have a cross-sectional area of the aluminum end and the copper end are maintained at temperatures of and respectively. the thermal conductivities of aluminum and copper are 205 w/m ∙ k (aluminum) and 385 w/m ∙ k (copper). what is the temperature of the aluminum-copper junction in the rod with steady state heat flow?