Hooke's Law states that if a spring is not stretched beyond its elastic limit, the force that acts on it is directly proportional to the extension of the spring.
Elastic Limit
The elastic limit of a spring is defined as the maximum force that can be applied to a spring such that the spring will be able to be restored to its original length when the force is removed.Equation derived from Hooke's Law
From Hook's Law, we can derived that
Spring Constant
It is a measure of the stiffness of a spring or elastic object.
Graph of Streching Force - Extension
Area below the graph = Work done
F-x graph and spring constant
The higher the gradient, the greater the spring constant and the harder (stiffer) spring.
For example, the stiffness of spring A is greater than spring B.