This article will be permanently flagged as inappropriate and made unaccessible to everyone. Are you certain this article is inappropriate? Excessive Violence Sexual Content Political / Social
Email Address:
Article Id: WHEBN0001318086 Reproduction Date:
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min) is a measure of the frequency of rotation, specifically the number of rotations around a fixed axis in one minute. It is used as a measure of rotational speed of a mechanical component. In the French language, tr/mn (tours par minute) is the common abbreviation. The German language uses the abbreviation U/min or u/min (Umdrehungen pro Minute).
According to the International System of Units (SI), rpm is not a unit. This is because the word revolution is a semantic annotation rather than a unit. The annotation is instead done as a subscript of the formula sign if needed. Because of the measured physical quantity, the formula sign has to be f for (rotational) frequency and ω or Ω for angular velocity. The corresponding basic SI derived unit is s^{−1} or Hz. When measuring angular speed, the unit radians per second is used.
Here the sign ↔ (correspondent) is used instead of = (equal). Formally, hertz (Hz) and radian per second (rad/s) are two different names for the same SI unit, s^{−1}. However, they are used for two different but proportional ISQ quantities: frequency and angular frequency (angular speed, magnitude of angular velocity). The conversion between a frequency f (measured in hertz) and an angular velocity ω (measured in radians per second) are:
Thus a disc rotating at 60 rpm is said to be rotating at either 2π rad/s or 1 Hz, where the former measures the angular velocity and the latter reflects the number of revolutions per second.
If the non-SI unit rpm is considered a unit of frequency, then 1~\text{rpm} = \frac{1}{60}~\text{Hz}. If it instead is considered a unit of angular velocity and the word "revolution" is considered to mean 2π radians, then 1~\text{rpm} = \frac{2\pi}{60}~\text{rad/s}.
Sound, Second, Wave, Radio, South America
Litre, Ampere, Force, Pressure, Mass
Linguistics, Semantic Web, Semiotics, Logic, Language
Din, Torque, Motive power, Power (physics), Kilowatt
Ducati, Revolutions per minute, Automotive industry, Fuel, Ducati Pantah
Volkswagen Group, Torque, Power (physics), German language, Litre
Inline-four engine, Petrol engine, Czech Republic, Torque, Turbocharger
Venezuela, Mexico, Dearborn, Michigan, Fastback, Torque