Objectives
- Determine the relation between force and extension of a spring and a rubber band
Introduction
A number of physical systems exhibit a linear restoring force when displaced from their equilibrium position. This is described by the relation;
F = -ks Hooke's Law
F is the restoring force of the system
k is a proportionality constant often referred to as the spring constant
s is the displacement from equilibrium position.
Displacement s=P-P0 where P0 is equilibrium position (no force acting at P0)
and P is displaced position.
Notice this relation is linear (having the appearance of y=mx+b where m=slope and b=0). Applying twice the force will double the displacement. Larger values of k, the spring constant, represent stiffer systems that are harder to stretch.
Hooke's law describes a spring over a limited range of displacements (the relation will not hold if a spring is stretched too far). In this lab you will also consider how well it holds for rubber bands.
References