A wood beam with E, -8.75 GPa, 100 mm wide by 220 mm deep, has an aluminum plate E. = 70 GPa with a net section 80 mm by 20 mm securely fastened to its bottom face, as shown below. Dimensions are given in millimeters. The beam is subjected to a bending moment of 20 kNm around a horizontal axis. Calculate the maximum stresses in both materials (a) using a transformed section of wood and (b) using a transformed section of aluminum. 220 20 100