updated physics/archimedes_principle.py

physics/archimedes_principle_of_buoyant_force.py

@@ -0,0 +1,63 @@
+"""
+Calculate the buoyant force of any body completely or partially submerged in a static
+fluid.  This principle was discovered by the Greek mathematician Archimedes.
+
+Equation for calculating buoyant force:
+Fb = ρ * V * g
+
+https://en.wikipedia.org/wiki/Archimedes%27_principle
+"""
+
+
+# Acceleration Constant on Earth (unit m/s^2)
+g = 9.80665  # Also available in scipy.constants.g
+
+
+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 the object (m^3)
+        gravity: Acceleration from gravity. Gravitational force on the system,
+            The default is Earth Gravity
+    returns:
+        the buoyant force on an object in Newtons
+
+    >>> archimedes_principle(fluid_density=500, volume=4, gravity=9.8)
+    19600.0
+    >>> archimedes_principle(fluid_density=997, volume=0.5, gravity=9.8)
+    4885.3
+    >>> archimedes_principle(fluid_density=997, volume=0.7)
+    6844.061035
+    >>> archimedes_principle(fluid_density=997, volume=-0.7)
+    Traceback (most recent call last):
+        ...
+    ValueError: Impossible object volume
+    >>> archimedes_principle(fluid_density=0, volume=0.7)
+    Traceback (most recent call last):
+        ...
+    ValueError: Impossible fluid density
+    >>> archimedes_principle(fluid_density=997, volume=0.7, gravity=0)
+    0.0
+    >>> archimedes_principle(fluid_density=997, volume=0.7, gravity=-9.8)
+    Traceback (most recent call last):
+        ...
+    ValueError: Impossible gravity
+    """
+
+    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
+
+    doctest.testmod()