Search results
Results from the WOW.Com Content Network
Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10 −6 metre).
Conversion of units is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to include replacement of a quantity with a corresponding quantity that describes the same physical property.
An input unit can be converted to any number of output units—the outputs are specified as a "combination" by separating unit codes with a space (" ") or a plus ("+"). Using a space as a separator does not work if any of the unit codes contains a space.
The atomic units have been chosen to use several constants relating to the electron: the electron mass, the elementary charge, the Coulomb constant and the reduced Planck constant. The unit of energy in this system is the total energy of the electron in the Bohr atom and called the Hartree energy. The unit of length is the Bohr radius.
Units of logarithmic frequency ratio include the octave, corresponding to a factor of 2 in frequency (precisely) and the decade, corresponding to a factor 10. The ISQ recognizes another logarithmic quantity, information entropy, for which the coherent unit is the natural unit of information (symbol nat). [citation needed]
The kelvin is defined by setting the fixed numerical value of the Boltzmann constant k to 1.380 649 × 10 −23 J⋅K −1, (J = kg⋅m 2 ⋅s −2), given the definition of the kilogram, the metre, and the second.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The barn (b) is a unit of area used in nuclear physics equal to one hundred femtometres squared (100 fm 2 = 10 −28 m 2). The are (a) is a unit of area equal to 100 m 2. The decare (daa) is a unit of area equal to 1000 m 2. The hectare (ha) is a unit of area equal to 10 000 m 2 (0.01 km 2).