Final answer:
Biting taffy illustrates shear stress, which is when opposite forces cause an object to deform and break.
Step-by-step explanation:
Biting off a piece of taffy is an example of shear stress. This type of stress occurs when two opposite forces are applied along the top and bottom of an object, like taffy, causing it to shear or tear. In the case of taffy, your teeth apply force in opposite directions to break off a piece. Shear stress is a common concept in material science and engineering, which describes how materials deform and break under various forces.