This quantity is located on the main diagonal of the (*) stress tensor.
In the free-electron model, this quantity equals two-fifths times the number density times the Fermi energy. In SI units, the value of this quantity possessed by a B-field is equal to B squared divided by twice the permeability of free space. One form of this quantity is equal to the time average of the Poynting vector divided by the speed of light. This quantity is located on the main diagonal of the (*) stress tensor. For a column of fluid, the change in this quantity is equal to the density of the fluid times "little g" times the height of the column, which allows for this quantity to be measured using a manometer or a barometer. For 10 points, name this quantity defined as force per unit area, which is measured in units such as atmospheres and Pascals.
In the free-electron model, this quantity equals two-fifths times the number density times the Fermi energy.
pressure [prompt on "P," prompt on "normal stress," accept more specific answers like radiation pressure or hydrostatic pressure]