天天模拟器(天天安卓模拟器下载) V2.1.3官方版
| centimetre | |
|---|---|
 A carpenter's ruler with centimetre divisions | |
| General information | |
| Unit system | SI |
| Unit of | length |
| Symbol | cm |
| Conversions | |
| 1 cm in ... | ... is equal to ... |
| millimetres | 10 mm |
| imperial & US system | ~0.3937 in |
A centimetre (International spelling) or centimeter (American English), with SI symbol cm, is a unit of length in the International System of Units (SI) equal to one hundredth of a metre, centi- being the SI prefix for a factor of 1/100.[1] Equivalently, there are 100 centimetres in 1 metre. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units.
Though for many physical quantities, SI prefixes for factors of 103—like milli- and kilo-—are often preferred by technicians, the centimetre remains a practical unit of length for many everyday measurements; for instance, human height is commonly measured in centimetres.[2][3] A centimetre is approximately the width of the fingernail of an average adult person.
Equivalence to other units of length
[edit]| 1 centimetre | = 10 millimetres |
| = 0.01 metres | |
| = 0.3937 inches (There are exactly 2.54 centimetres in one inch.) |
One millilitre is defined as one cubic centimetre, under the SI system of units.
Other uses
[edit]In addition to its use in the measurement of length, the centimetre is used:
- sometimes, to report the level of rainfall as measured by a rain gauge[4]
- in the CGS system, the centimetre is used to measure capacitance, where 1 cm of capacitance = 1.113×10?12 farads[5]
- in maps, centimetres are used to make conversions from map scale to real world scale (kilometres)
- to represent second moment of areas (cm4)
- as the inverse of the Kayser, a CGS unit, and thus a non-SI metric unit of wavenumber: 1 kayser = 1 wave per centimetre; or, more generally, (wavenumber in kaysers) = 1/(wavelength in centimetres). The SI unit of wavenumber is the inverse metre, m?1.
Unicode symbols
[edit]For the purposes of compatibility with Chinese, Japanese and Korean (CJK) characters, Unicode has symbols for:[6]
- centimetre – U+339D ㎝ SQUARE CM
- square centimetre – U+33A0 ㎠ SQUARE CM SQUARED
- cubic centimetre – U+33A4 ㎤ SQUARE CM CUBED
These characters are each equal in size to one Chinese character and are typically used only with East Asian, fixed-width CJK fonts.
See also
[edit]References
[edit]- ^ "Decimal multiples and submultiples of SI units". Bureau International des Poids et Mesures. 2014. Retrieved 5 July 2015.
- ^ "Using the BMI-for-Age Growth Charts". cdc.gov. Centers for Disease Control. Archived from the original on 30 January 2014. Retrieved 5 July 2014.
- ^ Price, Beth; et al. (2009). MathsWorld Year 8 VELS Edition. Australia: MacMillan. p. 626. ISBN 978-0-7329-9251-4.
- ^ "Rain Measurement". www.weathershack.com.
- ^ Weisstein, Eric W. "Capacitance -- from Eric Weisstein's World of Physics". scienceworld.wolfram.com.
- ^ CJK Compatibility excerpt from The Unicode Standard, Version 10.0.
External links
[edit]| International | |
|---|---|
| National | |
