Consider a three-dimensional state of stress characterized by: xx = 3,000 yy = 2,000 xy = 0.

Consider a three-dimensional state of stress characterized by:
σxx = 3,000 σyy = 2,000 τxy = 0.
σzz = 4,000 τzx = 0. τyz = 2,500
where units are psi and compression is positive. Find: the magnitude and direction of the principal stresses and illustrate with a sketch