What does Hooke's Law describe?

Hooke's Law specifically states that the force exerted by a spring is directly proportional to the amount it is stretched or compressed from its rest position, as long as this deformation is within the elastic limit of the spring. Mathematically, it can be expressed as ( F = kx ), where ( F ) is the force applied to the spring, ( x ) is the displacement from the equilibrium position, and ( k ) is the spring constant, which measures the stiffness of the spring.

In the context of this question, understanding Hooke's Law is fundamental in fields involving mechanics and materials, as it helps predict how materials will behave when subjected to forces. The other options pertain to different physical principles: one relates to kinematics, another deals with fluid dynamics, and the last is associated with the concept of mass-energy equivalence in physics. Consequently, recognizing Hooke's Law allows for applications in various practical situations, such as designing springs for machinery or testing materials under loads.