3. (20 points) Two blocks of rubber, each 80 mm long by 40 mm wide by 20 mm thick, are bonded to a rigid support mount and to moveable plate (1). When a force P=2800N is applied to the assembly, plate (1) deflects 8 mm horizontally. Determine the shear modulus of the rubber used for the blocks. FBD 20mm 40 mm (D) 20 mm 80 mm 20 88 = 0.4 20