Astate of stress that occurs at a point on the free surface of the of a solid body is σ x= 50 mpa , σ y =10 mpa , and τxy = −15 mpa xy τ .a. evaluate the two principal normal stresses and the one principal shear stress that can be found by coordinate system rotations in the x-y plane and give the coordinate system rotations. b. determine the maximum normal stress and the maximum shear stress at this point. c. sketch the rotations and stress magnitudes