The strains measured by strain gages on a block of an isotropic material with sample axes x and y are: sJr = 443.0 ppm, 5}. = 5.42} ppm, and VII = 2111:! ppm. The elastic modulus {E} and Poisson's ratio [1!] are 15K]I GPa and ELSE. respectively. 1 v D Note: Em = :1 _V _1 E: v e e 'What are the principal stresses and their orientations with respect to the sample axes? 1.I' n