2). Two planes, 'a' and 'b', are separated by an unknown angle 0. On plane 'a', Normal stress a = 10 kPa and shear stress ta = +2 kPa. Plane 'a' lies 15 degrees from horizontal (shown in figure below). The stresses on plane b are b = 9 kPa and shear stress ta=-3 kPa. Determine the following: a) Find the major and minor principal stresses and their orientation. b) Find the stresses on the horizontal plane. c) Find the angle between planes 'a' and 'b'. 10 kPa 2 kPa Horizontal plane 15 Plane a On plane b: = 9 kPa, T = -3 kPa, 0 = ? from plane a