Hooke’s Law

If we take a metal wire or a spring and hang it from the ceiling it will have a natural, unstretched length of l metres. If we then attach masses to the bottom of the wire is will begin to increase in length (stretch). The amount of length it has increased by we will call the extension and represent by e.

If the extension increases proportionally to the force applied it follows Hooke’s Law:

The force needed to stretch a spring is directly proportional to the extension of the spring from its natural length

So it takes twice as much force to extend a spring twice as far and half the force to extend it half as far.

We can write this in equation form: or

Here k is the constant that shows us how much extension in length we would get for a given force. It is called...