A unit of angular velocity, used particularly for rotation rates in mechanics. One r/min equals 0.104 720 radian per second. The tachometers on auto dashboards are usually calibrated in units of 1000 r/min
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}