Spring Forces

A spring exerts a force proportional to how much it stretches or compresses from its natural length. This is Hooke's Law:

Here $F_s$ is the spring force magnitude, $k$ is the spring constant (in N/m), and $\Delta x$ is the displacement from natural length.

Critical Point: The spring force depends only on $\Delta x$, the displacement from the spring's natural (unstretched, uncompressed) length—sometimes called the equilibrium position. It does not matter where the spring is located in space or what else is happening. Only $\Delta x$ matters.

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