$***$Thoroughly solve and show each and every problem, plz and thank you!!!$***$ Question $3(15$ points$).$ The cantilevered bar in the figure is made from a ductile material $($Yield Strength $=60k.)$ and is statically loaded with $F_x=300lbf,F_y=250lbf,$ and $F_z=0.$ Analyze the stress situation in the small diameter at the shoulder at A by obtaining the following information.

a$.(2$pts$)$ Determine the precise location of the critical stress element at the cross section at A$.$

b$.(8$pts$)$ Sketch the eritical stress element and determine magnitudes and directions for all stresses acting on it$.$

c$.(5$pts$)$ For the critical stress element, determine the principal stresses and maximum shear stress.