The given state of plane stress is known to exist on the surface of a machine component. knowing that e 5 200 gpa and g 5 77.2 gpa, determine the direction and magnitude of the three principal strains

(a) by determining the corresponding state of strain [use eq. (2.43) and eq. (2.38)] and then using mohr’s circle for strain,

(b) by using mohr’s circle for stress to determine the principal planes and principal stresses and then determining the corresponding strains.