Three toy blocks are glued together to form a beam that supp…

Three toy blocks are glued together to form a beam that supports a vertical shear force of 143 N. Each block has dimensions a = 20 mm and b = 60 mm. Determine the horizontal shear stress in the glue between blocks (1) and (2). The moment of inertia around the horizontal centroidal axis of the beam is 4,280,000 mm4.