A cantilever beam 1.5m long has a square box cross section with the outer width and height being 100mm and a wall thickness of 8mm. The beam carries a uniform load of 6.5kN/m along the entire length and, in the same direction, a concentrated force of 4kN at the free end.
(a) determine the max bending stress
(b) determine the max transervse shear stress
(c) determine the max shear stress in the beam