$(1)$ Use the method of superposition to determine the distribution of the normal stress xx throughout this beam, when this beam is loaded by a constant distributed load of $190$N$/$m$.$

$(2)$ Determine the maximum absolute value of xx and the location in the beam where it occurs. Consider the following cantilever W$310129$ I$-$beam supporting a long loading dock. The beam consists of steel with a Young's modules of $200$GPa and Poisson Ratio of $0\mathrm{.}31.$ At its left edge the beam is clamped and the beam is additionally resting on two supporting piers.

$\backslash (10\backslash$cap N I $/$ m $\backslash )$