Inverse second
| inverse second | |
|---|---|
| Unit system | SI |
| Unit of | frequency |
| Symbol | s-1 |
| Conversions | |
| 1 s-1in... | ... is equal to... |
| SI units | 1Hz |
Theinverse secondorreciprocal second(s−1), also calledper second,is aunitdefined as themultiplicative inverseof thesecond(a unit oftime). It is applicable forphysical quantitiesofdimensionreciprocal time,such asfrequencyandstrain rate.
It isdimensionallyequivalent to:
- hertz(Hz), historically known ascycles per second– the SI unit forfrequencyandrotational frequency
- becquerel(Bq) – the SI unit for the rate of occurrence of aperiodic or stochasticradionuclideevents
- baud(Bd) – the unit forsymbol rateover a communication link
- bits per second(bit/s) – the unit of bit rate
However, the special names and symbols above for s−1are recommend for clarity.[a][b]
Reciprocal second should not be confused withradian per second(rad⋅s−1), the SI unit forangular frequencyandangular velocity.As theradianis adimensionless unit,radian per second is dimensionally consistent with reciprocal second. However, they are used for differentkinds of quantity,frequency and angular frequency, whose numerical value differs by 2π.
Theinverse minuteorreciprocal minute(min−1), also calledper minute,is 60−1s−1,as 1 min = 60 s; it is used in quantities of type "countsper minute ", such as:
Inverse square second (s-2) is involved in the units of linearacceleration,angular acceleration,androtational acceleration.
See also
[edit]Notes
[edit]- ^"The SI unit of frequency is given as the hertz, implying the unit cycles per second; the SI unit of angular velocity is given as the radian per second; and the SI unit of activity is designated the becquerel, implying the unit counts per second. Although it would be formally correct to write all three of these units as the reciprocal second, the use of the different names emphasises the different nature of the quantities concerned."[1]
- ^"(d) The hertz is used only for periodic phenomena, and the becquerel (Bq) is used only for stochastic processes in activity referred to a radionuclide."[2]