1. The problem statement, all variables and given/known data The bottom surface (8 cm x 12 cm) of a rectangular block of cheese (3 cm thick) is clamped in a cheese grater. The grating mechanism moving across the top surface of the cheese, applies a lateral force of 20 N. The shear modulus, G, of the cheese is 3.7 kPa. Assuming the grater applies the force uniformly to the upper surface, estimate the lateral movement of the upper surface with respect to lower surface? My question is about shear stress. When calculating shear stress, which is force/area, which area do I use here? The 24 cm^2, or the 96 cm^2?