The discussion clarifies the relationship between strain and change in length as described by Hooke's Law. Strain is defined as a unitless measure representing the fractional change in length, while change in length is measured in meters (m). The conversation emphasizes that strain is an intensive property, meaning it does not accumulate across different sections of a material, whereas change in length is an extensive property that does accumulate. Understanding these distinctions is crucial for grasping the principles of mechanics and material science.
PREREQUISITESStudents of physics, engineering professionals, and anyone interested in understanding the mechanical properties of materials and their behavior under stress.
Orodruin said:It should be noted that Hooke's law relates stress ##\sigma## (i.e., the applied force per area) to strain ##\epsilon## as ##\sigma = E\epsilon##, where ##E## depends on the material. Thus, from force and cross-sectional area, you can know the strain, but not the change in length (for that you also need to know the original length).