Editing Second (section)

==Other units incorporating seconds==
A second is directly part of other units, such as [[frequency]] measured in [[hertz]] ([[inverse seconds]] or s<sup>−1</sup>), [[speed]] in meters per second, and [[acceleration]] in meters per second squared.  The metric system unit [[becquerel]], a measure of radioactive decay, is measured in inverse seconds and higher powers of second are involved in [[Fourth, fifth, and sixth derivatives of position|derivatives of acceleration]] such as [[jerk (physics)|jerk]]. Though many derivative units for everyday things are reported in terms of larger units of time, not seconds, they are ultimately defined in terms of the SI second; this includes time expressed in hours and minutes, velocity of a car in kilometers per hour or miles per hour, kilowatt hours of electricity usage, and speed of a turntable in rotations per minute.

Moreover, most other [[SI base units]] are defined by their relationship to the second: the [[meter]] is defined by setting the [[speed of light]] (in vacuum) to be 299 792 458&nbsp;m/s, exactly; definitions of the SI base units [[kilogram]], [[ampere]], [[kelvin]], and [[candela]] also depend on the second. The only base unit whose definition does not depend on the second is the [[Mole (unit)|mole]], and only two of the 22 named derived units, [[radian]] and [[steradian]], do not depend on the second either.