A square plate is 1.0 × 10-2 m thick, measures 3.0 × 10-2 m on a side, and has a mass of 7.2 × 10-2 kg. The shear modulus of the material is 2.0 × 1010 N/m2. One of the square faces rests on a flat horizontal surface, and the coefficient of static friction between the plate and the surface is 0.91. A force is applied to the top of the plate, as in Figure 10.29a. Determine

(a) The maximum possible amount of shear stress,

(b) The maximum possible amount of shear strain,

(c) The maximum possible amount of shear deformation DX (Figure 10.29b) that can be created by the applied force just before the plate begins to move.

AX Figure 10.29 (a) An example of a shear defor- mation. The shearing forces F and -F are applied parallel to the top and bottom covers of the book. (b) The shear deformation is AX. The area of each cover is A, and the thickness of the book is Lo- Area = A (b) (a)