In order to increase corrosion resistance, a 2-mm-thick cladding of aluminum has been added to a steel bar as shown. The modulus of elasticity is 200 GPa for steel and 70 GPa for aluminum. For a bending moment of 300 N.m, determine
(a) the maximum stress in the steel,
(b) the maximum stress in the aluminum,
(c) the radius of curvature of the bar.