The moment of inertia (MoI) is expressed as `kg * m^2` in SI units and as `lb_m * ft^2` in US units. The MoI represents the amount of torque around an axis that is required to cause a specified amount of change in angular momentum. This equation always output one unit of MoI in SI units.
If you are computing a moment of inertia and want to get out the appropriate units, compute the answer in Groovy without units and then multiply it by this constant. Your result should be in `kg * m^2`