The Hooke's Law Calculator computes the force to compress or extend a spring (Fx) to compress or extend a spring based on the spring constant (k) for the spring and a specified length (x).
INSTRUCTIONS:: Choose units and enter the following:
Force to Compress a Spring (Fx): The calculator computes the required force (Fx) in Newtons. However, this can be automatically converted to other force units via the pull-down menu.
Hooke's Law relates the restoring force, F, needed to extend or compress a spring to the length, X. The force can be applied to either extension or compression of the spring. The extension/compression is proportional to the force required and the constant, k, is characteristic of the spring's stiffness.
A compressed Spring
Force in this equation is directly proportional to elongation -- IFF the elongation is not too great. In other words if you stretch the spring with too much force, you can cause permanent deformation of the spring and the spring constant is altered.
Remember those Slinkys from when you were a kid that were damaged when they were stretched too far?
To stretch the spring we must do work and thus we get the associated equation W = ½• k•X².
Khan Academy's Intro to springs and Hooke's Law