Concentration total amount of all "other" constituents in a mixture: If formula_6 is much smaller than formula_26, the mole ratio is almost identical to the mole fraction. The SI unit is mol/mol. However, the deprecated parts-per notation is often used to describe small mole ratios. The mass fraction formula_33 is the fraction of one substance with mass formula_2 to the mass of the total mixture formula_35, defined as: The SI unit is kg/kg. However, the deprecated parts-per notation is often used to describe small mass fractions. The mass ratio formula_37 is defined as the mass of a constituent formula_2 divided by
Impulse (physics) Impulse (physics) In classical mechanics, impulse (symbolized by J or Imp) is the integral of a force, F, over the time interval, t, for which it acts. Since force is a vector quantity, impulse is also a vector in the same direction. Impulse applied to an object produces an equivalent vector change in its linear momentum, also in the same direction. The SI unit of impulse is the newton second (N⋅s), and the dimensionally equivalent unit of momentum is the kilogram meter per second (kg⋅m/s). The corresponding English engineering units are the pound-second (lbf⋅s) and the slug-foot per second (slug⋅ft/s).