In the unit force-mass meter-kilogram-second system, the base unit of length (equivalently, of distance) is the meter, and the base unit of time is the second. The name kilogram is applied to both the unit of mass and the unit of force (equivalently, of weight), though, since these are in fact different quantities, it would be better to refer to two separate units, the kilogram-mass and the kilogram-force, as base units of the unit force-mass meter-kilogram-second system.