Added archimedes principle (physics)

physics/archimedes_principle.py

@@ -0,0 +1,49 @@
+"""
+Calculates buoyant force on object submerged within static fluid.
+Discovered by greek mathematician, Archimedes. The principle is named after him.
+
+Equation for calculating buoyant force:
+Fb = ρ * V * g
+
+Source:
+- https://en.wikipedia.org/wiki/Archimedes%27_principle
+"""
+
+
+# Acceleration Constant on Earth (unit m/s^2)
+g = 9.80665
+
+
+def archimedes_principle(
+    fluid_density: float, volume: float, gravity: float = g
+) -> float:
+    """
+    Args:
+        fluid_density: density of fluid (kg/m^3)
+        volume: volume of object / liquid being displaced by object
+        gravity: Acceleration from gravity. Gravitational force on system,
+            Default is Earth Gravity
+    returns:
+        buoyant force on object in Newtons
+
+    >>> archimedes_principle(fluid_density=997, volume=0.5, gravity=9.8)
+    4885.3
+    >>> archimedes_principle(fluid_density=997, volume=0.7)
+    6844.061035
+    """
+
+    if fluid_density <= 0:
+        raise ValueError("Impossible fluid density")
+    if volume < 0:
+        raise ValueError("Impossible Object volume")
+    if gravity <= 0:
+        raise ValueError("Impossible Gravity")
+
+    return fluid_density * gravity * volume
+
+
+if __name__ == "__main__":
+    import doctest
+
+    # run doctest
+    doctest.testmod()