3. Assume the plane stress state: ơ1 = 0, 02 = 20, T12 = 15 (all stresses in ksi). If oz alone is increased until the maximum shear stress t1, in the material reaches ±20 ksi, what is the value of o,...

Extracted text: 3. Assume the plane stress state: ơ1 = 0, 02 = 20, T12 = 15 (all stresses in ksi). If oz alone is increased until the maximum shear stress t1, in the material reaches ±20 ksi, what is the value of o, at this point? HINT: this is relatively easy to figure out if you construct a Mohr's circle for the initial stress state and then consider what happens if o, is replaced with Ao2 and you solve for A when the maximum shear stress (from the circle geometry) reaches ±20 ksi.