The highway pole $($AB$)$ given in the figure carries two direction signs. The signs are fixed to the pole. The $100$x$50$ cm plate weighs $200$ kg$,$ the $50$x$50$ cm plate weighs $100$ kg$,$ and the plates are subject to wind loads perpendicular to their planes. Calculate the maximum and minimum normal and maximum shear stresses that will occur on the pole. $($Note: Neglect the pole's own weight.$)$