What is the formula used to calculate the elastic force that occurs when the body is stretched and compressed?

For springs and ropes it is
-kx, where x is the elongation (or contraction) of the body
kΔl, where Δl = l1-l0 (End length minus start)
In both formulas, k is the rigidity of the body



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.