Revolutions Per Minute Article Index for
Revolutions
Shopping
Revolutions
Articles about
Revolutions Per Minute
Website Links For
Revolutions
 

Information About

Revolutions Per Minute






Revolutions per minute (abbreviated '''rpm''', '''RPM''', '''r/min''', or '''min-1''') is a Unit of Frequency , commonly used to measure Rotational Speed , in particular in the case of Rotation Around A Fixed Axis . It represents the number of full rotations something makes in one minute.


EXAMPLES

  • Gramophone (phonograph) Records typically rotate steadily at 16, 33⅓, 45 or 78 rpm.

  • Audio CD rotation rates vary from about 500 rpm when reading the innermost data track, to 180 rpm when reading tracks near the outer edge.

  • The sweep second hand of a clock or watch rotates at 1 rpm.

  • A Washing Machine 's tub may rotate at 600 to 1600 rpm during the spin cycle.

  • An Automobile 's Engine typically varies between 700 and 7000 rpm.

  • A piston Aircraft Engine typically rotates between 2000 and 3000 rpm.

  • A Racing Car engine's limits are much higher, as high as 20,000 rpm in Formula One .

  • Gas Turbine engines rotate at tens of thousands of rpm. Jetcat model aircraft turbines are capable of over 100,000 rpm with the fastest hitting 165,000 rpm http://www.jetcatusa.com/p60.html

  • A computer's Hard Drive rotates at 3600, 5400, or 7200 rpm on IDE types and 10,000 or 15,000 rpm on some SATA and SCSI and Fibre Channel drives.

  • A 52× CD-ROM drive can rotate a CD as fast as 10,350 rpm.

  • A Zippe-type Centrifuge for enriching uranium spins at 90,000 rpm or faster.



SYMBOLS OTHER THAN ''RPM''

Standards Organization s generally recommend the symbol ''r/min'', which better follows the general principles for forming unit symbols. But this is not enforced in fully metric countries as an international standard; for example, the French use the symbol '''''tr/mn''''' ('tours par minute').


COMPARED TO ''FREQUENCY'' AND ''ANGULAR SPEED''

The International System Of Units (SI) unit of Frequency is the Hertz (Hz) :
:1 r/min = 1/60 Hz
  • This is often used for measuring waves, such as radio and sound.


The SI unit of Angular Speed is the Radian per Second :
:1 r/min = 2π rad/min = 2π/60 rad/s = 0.10471976 rad/s

However, there is no movement to use either of these units of measure (which are primarily used in Physics ) to replace ''revolutions per minute'' when measuring the rotational speed of machinery.


SEE ALSO