1) Draw a Mohr's circle diagram properly labeled for the following plane stress state:
σx = -8 MPa
σy = 7 MPa
τxy = 6 MPa (clockwise)
2) Find the principal normal and shear stresses, and determine the angle from the x-axis to σ1.
3) Also, draw the stress elements correctly aligned with respect to xy coordinates, and draw another stress element to show τ1 and τ2.