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47.2: Introduction

  • Page ID
    29391
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    The system of units used in the physical sciences is based on the metric system.  Numbers that describe physical quantities range from the very large to the very small, so a set of standard prefixes are used to designate convenient-sized units that differ by multiples of ten.  Every step in the metric system is a multiple of 10.  

    Table \(\PageIndex{1}\): Prefixes to designate convenient-sized units that differ by multiples of ten

    Multiple

    Prefix

    Symbol

    \(10^{24}\)

    yotta

    Y

    \(10^{21}\)

    zetta

    Z

    \(10^{18}\)

    exa

    E

    \(10^{15}\)

    peta

    P

    \(10^{12}\)

    tera

    T

    \(10^{9}\)

    giga

    G

    \(10^{6}\)

    mega

    M

    \(10^{3}\)

    kilo

    k

    \(10^{1}\)

    deca

    da

    \(10^0\)

       

    \(10^{-1}\)

    deci

    d

    \(10^{-2}\)

    centi

    c

    \(10^{-3}\)

    milli

    m

    \(10^{-6}\)

    micro

    μ

    \(10^{-9}\)

    nano

    n

    \(10^{-12}\)

    pico

    p

    \(10^{-15}\)

    femto

    f

    \(10^{-18}\)

    atto

    a

    \(10^{-21}\)

    zepto

    z

    \(10^{-24}\)

    yocto

    y

    The United States continues to use English units.  Conversion factors utilize equivalent sized measurements, to change from one unit to another.  For example, 1 inch and 2.54 centimeters measure the exact same length.  Converting from one unit to another requires multiplying by the appropriate conversion factor.

    Table \(\PageIndex{2}\): English to Metric conversion

    English to Metric

    1 inch = 2.54 centimeter

    1 mile = 1609 meters

    0.2248 lb = 1 Newton

    Example: [Measurement] x [Conversion Factor] = New Number

    \[12 \cancel{\text { inches }} \times \dfrac {2.54 \text { centimeters}}{1 \cancel {\text { inch}}}  =  30.48 \text { centimeters} \nonumber \]

    The inches in the numerator and the inches in the denominator cancel

    Contributors and Attributions


    47.2: Introduction is shared under a CC BY license and was authored, remixed, and/or curated by LibreTexts.

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