In the preceding lesson, we have defined Hooke's law but the discussion was focused more on one-dimensional behavior. In this lesson, we'll extend this theory to the more general three-dimensional case. The final form of the equations may seem overwhelming so we'll start with a simple 3D case and add details to it on our way to a general and a final form.

This information is important as we perform most calculations in three dimensions. Also, in the case of anistropic materials such as wood or woven composites, the properties change in different directions so it's important to discuss Hooke's law in 3D space.