Experiment: Find the spring constant
The spring constant of a spring can be found by carrying out an experiment.
The unloaded length of a spring is measured.
Slotted masses are added to the spring.
Record each stretching force in N and the corresponding length of the spring.
The extension is the new length minus the unloaded length.
Provided that the limit of proportionality is not exceeded, a graph of stretching force against extension is a straight line through the origin, because Hooke鈥檚 Law is obeyed.
The gradient of the line \(\frac{\text{F}}{\text{e}}\) is the spring constant, k.
Hooke鈥檚 Law is obeyed up to the limit of proportionality.
Beyond this point, stretching force and extension are no longer directly proportional and the graph begins to curve.
If a material is stretched further still, and beyond a point known as the The maximum amount that an object can be stretched or squashed before it is no longer able to return to its original shape. , it does not return to its original length when the force is removed.