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).
Hooke's law
In SI units, displacements are measured in meters (m), and forces in newtons (N or kg·m/s). Therefore, the spring constant , and each element of the tensor , is measured in newtons per meter (N/m), or kilograms per second squared (kg/s).