Across a particular plane in a rock, the state of stress is found to be 1.2 kbar (normal) and -0.6 kbar (shear). On a plane at right angles to this plane the state of stress is 0.6 kbar (normal) and 0.6 kbar (shear). Use a Mohr diagram to answer questions 3a and 3b.
a. Assuming stress 2 is parallel to the intersection of these two planes, what are the values of stress 1 and stress 3?
b. What are the values of normal stress and shear stress on a plane containing stress 2 and whose normal is at an angle of +65 degrees to the stress 1 direction?
c. If stress 2 is 0.7 kbar, what is the mean stress for this stress state? What is the deviatoric normal and shear stress on the plane in part b?