Hooke's Law fails when a material reaches its:2 marksbreakdownelastic limitfracture stress

Hooke's Law fails when a material reaches its elastic limit.

Step 1: Understanding Hooke's Law Hooke's Law states that the force needed to extend or compress a spring by some distance is proportional to that distance. This means that the strain (deformation) in a material is proportional to the applied stress as long as this stress does not exceed a certain limit.

Step 2: Understanding Elastic Limit The elastic limit is the maximum stress or force per unit area within a solid material that can arise before the onset of permanent deformation. When stresses beyond this limit occur, the material is no longer able to return to its original shape and size after the stress is removed.

Step 3: Hooke's Law and Elastic Limit Hooke's Law is only valid up to the elastic limit of a material. Beyond this point, the material will deform plastically, meaning it will not return to its original shape once the load is removed. Therefore, Hooke's Law fails when a material reaches its elastic limit.