Definition:Spring

Definition
A spring is a mechanical device for storing elastic potential energy.

It works by resisting a force which acts so as to deform it. The greater the deformation, the greater the force.

Ideal Spring
An ideal spring obeys Hooke's Law:
 * $\mathbf F = -k \mathbf x$

where:
 * $\mathbf F$ is the force caused by a displacement $\mathbf x$;
 * $k$ is the constant of proportion.

The negative sign indicates that the force pulls in the opposite direction to that of the displacement imposed.

Spring Force Constant
The constant of proportionality $k$ is known as the force contant.

Its value depends on the particular spring under investigation.

The SI unit of the spring force constant is newtons per meter: $\mathrm N \ \mathrm m^{-1}$.