For the beam and loading shown, determine the stress components at point B, located just slightly above the junction of the lower flange and the web, in section a-a of the cantilever beam. As shown on the diagram below, section a-a is located 250 mm to the right of the fixed end. Draw a differential element that clearly shows the stress components acting at point B. Note: it is important to clearly indicate the coordinate system in every drawing. 4 kN 2 kN -250 mm ----250 mm 300 mm a a 20 mm 70 mm B 20 mm 50 mm