Determine the principal planes and the principal stresses for the state of plane stress resulting from the superposition of the two states of stress shown. given: x 50 mpa and y 30 mpa. ay 80 mpa 30° + the orientation of the principal plane in the first quadrant is 120 the orientation of the principal plane in the second quadrant is 210 mpa, and the minimum principal the maximum principal stress is mра. stress is