The Spring Constant

The spring constant gives us an idea of the stiffness (or stretchiness) of the material.

If we rearrange Hooke’s Law we get:

If we record the length of a spring, add masses to the bottom and measure its extension we can plot a graph of force against extension. The gradient of this graph will be equal to the spring constant.

A small force causes a large extension the spring constant will be small – very stretchy

A large force causes a small extension the spring constant will be large – not stretchy

Spring Constant is measured in Newtons per metre, N/m