Pressure measurement
Many other hybrid units are used such as mmHg/cm or grams-force/cm (sometimes as kg/cm without properly identifying the force units). Using the names kilogram, gram, kilogram-force, or gram-force (or their symbols) as a unit of force is prohibited in SI; the unit of force in SI is the newton (N).
Joule-second
The joule-second also appears as the unit of measure in classical mechanics for the angular momentum of a rotating object and in quantum mechanics within the definition of Planck's constant. Angular momentum is the product of an object’s moment of inertia, in units of kg∙m and its rotational velocity in units of m∙s∙m, or simply s (i.e., Hz). This product of moment of inertia and rotational velocity yields kg∙m∙ s or the joule-second. Planck's constant represents the energy of a wave, in units of joule, divided by the frequency of that wave, in units of s. This quotient of energy and frequency also yields the joule-second (J∙s).