EXPLAIN WHAT HAPPENS TO A ROCK AFTER THEIR ELASTIC LIMIT IS PASSED.
It breaks, because it undergoes brittle fracture. Metals and other ductile materials continue to stretch beyond the elastic limit.
When a rock is subjected to increasing stress, it undergoes deformation, which means it changes its shape. Initially, the rock follows Hooke's law, which states that stress is directly proportional to the strain (deformation) as long as the rock remains within its elastic limit.
However, if the applied stress exceeds the elastic limit of the rock, it undergoes permanent deformation. This means that when the stress is removed, the rock will not return to its original shape and size. Instead, the rock will retain the deformation and exhibit a permanent change.
The specific behavior of the rock after passing its elastic limit depends on various factors such as the type of rock, its composition, and the magnitude of stress applied. In some cases, the rock may display plastic deformation, where it undergoes significant distortion without fracturing. In other cases, the rock may experience brittle fracture, resulting in the formation of cracks or complete fragmentation.
To observe what happens to a rock after its elastic limit is passed, you can perform an experiment. Take a rock sample of known composition and subject it to increasing amounts of stress using a testing machine like a hydraulic press. Measure the deformation of the rock at each increment of stress and plot a stress-strain curve. The elastic limit is the point on the curve where the rock starts to deviate from a linear relationship between stress and strain.
Experiments like these help scientists and engineers understand the mechanical properties of different rocks and materials, which is essential for designing structures and predicting their behavior under stress.