محول السرعة والسرعة

Speed is a scalar quantity — it only has magnitude (e.g., 50 km/h). Velocity is a vector — it has both magnitude and direction (e.g., 50 km/h north). For unit conversion, only the magnitude matters.

A knot is one nautical mile per hour. One nautical mile = 1852 meters (defined as one minute of arc of latitude). Knots are used in aviation and marine navigation. 1 knot = 0.5144 m/s = 1.852 km/h.

The speed of sound in air depends on temperature: a = 331.3 + 0.606×T(°C) m/s. At 20 °C, a ≈ 343.2 m/s. At higher altitudes where temperature drops, the speed of sound decreases, so the same velocity corresponds to a higher Mach number.

Surface speed = π × D × n / 60, where D is diameter in meters and n is RPM. The result is in m/s. For ft/min (common for cutting tools), use: Surface speed = π × D(ft) × RPM.

Vibration velocity is typically measured in mm/s (metric, per ISO 10816/20816) or in/s (imperial). These are peak or RMS values of oscillatory velocity, not the same as translational speed of the machine.