At a point in a material under stress, the resultant stress is 120 MPa inclined at an angle of 30° to the normal on the plane. On another plane, perpendicular to the plane of resultant stress of +120MPa, the normal component of resultant stress is +80 MPa. What is the resultant stress on the second plane? What are the principal stresses and the principal angles with respect to the first plane (Fig. 3.32)?
