Two solid cylindrical rods AB and BC are welded together at B and loaded as shown. Take d = 30 mm, d2 = 50 mm, and P 60 kN. = P 0.9 m 125 kN 125 kN 1.2 m Find the average normal stress at the midsection of rod BC (Input the answer with the appropriate sign.) The average normal stress at the midsection of rod BC is MPa.