Problem $2(6$ points$)$

A flat bar of the cross$-$section $(bh)$ is subjected to the tensile load $P,$ as shown in the following

figure. Find the normal and shear stresses acting on an inclined plane defined by the unit normal

vector $n=[0,\frac{1}{\sqrt[\phantom{2}]{3}},\sqrt[\phantom{2}]{\frac{2}{3}}].$