# Ballast and neutral-buoyancy sizing
# Scope: Added dense ballast to cancel an existing positive buoyancy; includes ballast displacement.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

excessBuoyancy = 20 N
fluidDensity = 1000 kg/m^3
ballastDensity = 7800 kg/m^3
gravity = 9.81 m/s^2

mass := excessBuoyancy/(gravity*(1-fluidDensity/ballastDensity)) [kg]

check ballast mass budget: mass <= 3 kg

scenario alternative: excessBuoyancy = 16 N