Add Hooke's Law implementation to physics

physics/hookes_law.py

@@ -0,0 +1,52 @@
+"""
+Hooke's Law states that the force needed to extend or compress a spring
+is proportional to the distance of that extension or compression.
+
+    F = -k * x
+
+Where:
+    F = Force applied (in Newtons)
+    k = Spring constant (in Newtons per meter, N/m)
+    x = Displacement from equilibrium (in meters)
+
+The negative sign indicates the force is a restoring force (opposite to displacement).
+
+Reference: https://en.wikipedia.org/wiki/Hooke%27s_law
+"""
+
+
+def hookes_law(spring_constant: float, displacement: float) -> float:
+    """
+    Calculate the restoring force of a spring using Hooke's Law.
+
+    Parameters:
+        spring_constant: stiffness of the spring in N/m (must be positive)
+        displacement: extension or compression in meters
+
+    Returns:
+        Restoring force in Newtons (negative means opposing displacement)
+
+    >>> hookes_law(spring_constant=50, displacement=0.1)
+    -5.0
+    >>> hookes_law(spring_constant=100, displacement=0.5)
+    -50.0
+    >>> hookes_law(spring_constant=200, displacement=-0.2)
+    40.0
+    >>> hookes_law(spring_constant=0, displacement=0.1)
+    Traceback (most recent call last):
+        ...
+    ValueError: Spring constant must be positive.
+    >>> hookes_law(spring_constant=-10, displacement=0.1)
+    Traceback (most recent call last):
+        ...
+    ValueError: Spring constant must be positive.
+    """
+    if spring_constant <= 0:
+        raise ValueError("Spring constant must be positive.")
+    return -spring_constant * displacement
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()