The Spring Equation
In 1660, British physicist Robert Hooke discovered a fundamental law of classical mechanics: the amount of force required to stretch a spring is directly proportional to how far you are trying to stretch it.
If you pull a spring 1 inch, it fights back with 10 pounds of force. If you pull it 2 inches, it fights back with exactly 20 pounds of force. This perfectly linear relationship is called Hooke's Law.
The Spring Constant ()
Every spring, rubber band, or piece of elastic metal in the world has a unique stiffness. This is represented by , the Spring Constant, measured in Newtons per meter ().
- A Low (like a slinky) means the spring is incredibly weak and stretches easily.
- A High (like the shock absorbers on a monster truck) means the spring is incredibly stiff and requires massive force to compress.
The Equation
Why is there a negative sign? Because Hooke's Law calculates the Restoring Force. If you pull the spring to the right (positive ), the spring fights back by violently pulling to the left (negative ).