Three loads are applied to the short rectangular post shown. The cross$-$sectional dimensions of the post are also shown. $[$Pz $=100$ kN$,$ Py $=190$ kN$,$ and Px $=55$ kN$,$ a$=140$ mm$,$ b$=70$ mm$,$ c$=70$ mm$,$ L$1=50$ mm$,$ L$2=30$ mm$]$

$1)$ Determine the moment Mx that is needed for calculation of stress at point K$.$

$2)$ Determine the moment Mz that is needed for calculation of stress at point K$.$

$3)$ Determine the magnitude of the total normal stress at point K$.$

$4)$ Determine the magnitude of the total shear stress at point K$.$