Imagine a spring attached at one end to a support and at rest (with no action at all).
When we apply a force F to the other end, the spring tends to warp (stretch or compress depending on the direction of the applied force).
In studying spring deformations and applied forces, Robert Hooke (1635-1703) found that spring deformation increases proportionally to force. Hence the following law, called Hooke's Law, was established:
F: intensity of the applied force (N);
k: spring elastic constant (N / m);
x: spring deformation (m).
The elastic constant of the spring depends mainly on the nature of the spring manufacturing material and its dimensions. Its most usual unit is N / m (newton per meter) but we also find N / cm; kgf / m, etc.
A 10kg body in equilibrium is attached to the end of a spring whose elastic constant is 150N / m. Considering g = 10m / s², what will be the spring deformation?
If the body is in equilibrium, the sum of the forces applied to it will be null, ie:
, because the forces have opposite directions.