As stated in the introduction, shear strength is another measure of the strength of a material. a shear force is a force that acts parallel to the plane in the material that breaks. a good example of a shear is that of a martial arts expert breaking boards or bricks with her hands. other applications in which shear forces and shear strength need to be known are geology, for studying earthquakes and landslides; fluid dynamics; and structural engineering. aluminum has a shear strength of 210 megapascals. when you bend aluminum foil around an edge (i. e., the edge of the box) and pull, you are effectively applying a shear force along the bent edge of the foil. if a roll of household aluminum foil is 30.0 centimeters wide and its thickness is approximately 15.0 micrometers, how much shear force is needed to pull off a sheet?