A rod consisting of two cylindrical portions AB and BC is restrained at both ends. Portion AB is made of steel (E_s = 200 GPa, ?_s = 11.7 × 10??/°C) and portion BC is made of brass (E_b = 105 GPa, ?_b = 20.9 × 10??/°C). Knowing that the rod is initially unstressed, determine the compressive force induced in ABC when there is a temperature rise of 50°C.