Hooke's law is one of the basic laws of mechanics. The law of elasticity, which is applicable to all solid materials, points out that within the elastic limit, the deformation of an object is proportional to the external force that causes the deformation. This law was discovered by British scientist Hooke, so it is called Hooke's law.

The expression of Hooke's law is f = kx, where k is a constant and a stubborn coefficient of an object. In the international system of units, the unit of F is cattle, the unit of X is meters, it is a deformation (elastic deformation), and the unit of K is cattle/meter. The stiffness coefficient is numerically equal to the elastic force of the spring when it is extended (or shortened) per unit length.