Convert Hertz (rotational) to Radians per second

The Hertz (rotational) (symbol: Hz) is a unit of angular velocity. Rotational frequency expressed in cycles per second — dimensionally identical to rev/s (1 Hz = 1 rev/s = 60 RPM = 2π rad/s) but more common in physics, vibration analysis, and rotor-dynamics contexts where the frequency-domain interpretation matters. Used in: rotor-dynamics critical-speed studies per API 684 and ISO 21940 (the first-bending-mode critical speed of a 200 MW steam turbine rotor is typically 25-35 Hz, well separated from the 50/60 Hz grid synchronous speed at 50/60 Hz exactly), NDT (Non-Destructive Testing) vibration surveys per ISO 10816, FFT spectral analysis of rotating-machinery vibration signatures (the 1× = running speed peak, 2× = misalignment, 3-10× = blade-pass or gear-mesh frequencies depending on machine type), and balancing-machine output per ISO 1940 / ISO 21940-11. NOT to be confused with Hz as an electrical / temporal / oscillatory frequency (though they share the same underlying '1/s' dimension and are sometimes deliberately conflated in spectral analysis).

It belongs to the metric measurement system.

Hertz (rotational) are commonly used in motor specifications, rotating machinery, and mechanical design.

The Radian per second (symbol: rad/s) is a unit of angular velocity. The SI unit of angular velocity (ISO 80000-3 §3-7), equal to the rate of change of angular displacement in radians per second. rad/s is the native unit of every physics and engineering formula involving rotational motion: rotational power P = τ·ω (torque × angular velocity), angular momentum L = I·ω (moment of inertia × ω), rotational kinetic energy KE = ½·I·ω², centripetal acceleration a = ω²·r, and the time-derivative form of angular position θ(t) where ω = dθ/dt. Mechanical engineering (drivetrain dynamics, turbomachinery analysis per ASME PTC 6), robotics control loops (PID position-loop tuning in radians per second for joint actuators), gyroscope output (MEMS rate gyros report rad/s natively on the I²C/SPI register), and physics simulations (Bullet Physics, Newton Dynamics, PhysX) all work in rad/s. Reference values: Earth's rotation 7.27 × 10⁻⁵ rad/s (one full turn per 24 h ≈ 86,164 s sidereal day); a typical automotive crankshaft at 6,000 RPM = 628 rad/s; helicopter rotor 30-40 rad/s. 1 rad/s ≈ 9.5493 RPM.

Radians per second are commonly used in motor specifications, rotating machinery, and mechanical design.