At a point in a material under stress, the intensity of resultant stress on a certain plane (AB) is 60 N/mm2 (tensile) inclined at 30° to the normal to that plane. The stress on an another plane (CA) at right angles to this has a normal tensile component of intensity 40 N/mm2. Find
a. the resultant stress on second plane
b. the principal stresses and orientations
c. maximum shear stress and orientations