Radian Per Second (rad/s)
The SI unit of angular velocity. One full turn is 2π (about 6.283) radians, so 1 rad/s is about 0.159 Hz.
1 radian per second = 0.1591549431 hertz (approximately).
About the radian per second
Physicists measure spin in radians per second because the angle then drops out of the equations neatly. Angular velocity is the rate of change of an angle, and its SI unit is the radian per second. Since the radian is dimensionless, the unit is dimensionally the same as 1 per second, so Wikipedia's article on angular velocity says rad/s is preferable, to avoid mixing it up with a rotation rate in hertz.
The link between the two is a factor of 2 pi. Angular velocity equals 2 pi times the frequency, so one rad/s is 1/(2 pi) hertz, about 0.159 Hz, and one hertz is about 6.283 rad/s. A disc turning at 60 revolutions per minute therefore spins at 1 Hz, which is 2 pi rad/s. The figure used on this site for the conversion is 0.15915494 hertz per radian per second, the same value to eight decimals.
Sources: Wikipedia: Angular velocity; Wikipedia: Hertz; Wikipedia: Revolutions per minute
Radian Per Second conversion chart
1 radian per second expressed in every other frequency unit:
| Unit | 1 radian per second |
|---|---|
| Hertz | 0.1591549431 |
| Kilohertz | 0.0001591549431 |
| Megahertz | 1.591549431×10⁻⁷ |
| Gigahertz | 1.591549431×10⁻¹⁰ |
| Revolutions Per Minute | 9.549296586 |
| Beats Per Minute | 9.549296586 |
| Terahertz | 1.591549431×10⁻¹³ |
| Millihertz | 159.1549431 |
| Degrees Per Second | 57.29577951 |
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