For the pier support shown in the figure below, determine: a) Internal normal force in the cross-section a-a. b) Internal bending moment in the cross-section a-a. c) Normal stress at the centroid of the cross-section a-a. d) Maximum normal stress due to bending within the cross-section a-a. e) Normal stress at point H. f) Normal stress at point K. 250 kN 3m Fig. a HK 400 KN 2m 250 mm 500 mm Fig. b Cross section a-a