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1.3: Calculations, Units, and Unit Conversion

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    102514
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    SI Base Units

    Quantity Unit Symbol
    Length meter m
    Mass kilogram kg
    Time second s
    Angle radian rad
    Temperature kelvin K

    SI Derived Units

    Quantity Symbol Units/Formula
    Acceleration - m/s2
    Area - m2
    Density - kg/m3
    Force N kg•m/s²
    Pressure/Stress Pa N/m2
    Pressure/Stress MPa N/mm²
    Weight N kg•m/s²
    Work J N•m

    SI Prefixes

    Prefix SI Symbol Factor
    giga G 1,000,000,000 = 109
    mega M 1,000,000 = 106
    kilo k 1,000 = 103
    milli m 0.001 = 10-3
    micro µ 0.000 001 = 10-6

    Unit Conversions

    Interactive File

    The table below shows how to convert units. Open this Excel file or look for the file in your course to access the interactive version that allows you to enter inputs to calculate outputs.

    Left to right

    These units multiplied by...-->

    ..this factor will...-->

    ..convert to these units.

    Reverse, right to left... Convert to these units...<-- <---this factor will... <---These units divided by...
    Length      
      inches 2.54 centimeters
      feet 0.3048 meters
      yards 0.9144 meters
      miles 1.609 kilometers
      miles 5,280 feet
    Area      
      square inches 645.2 square millimeters
      square feet 0.0929 square meters
      square yards 0.8361 square meters
    Volume      
      cubic inches 16,387 cubic millimeters
      cubic feet 0.02832 cubic meters
      cubic yards 0.7646 cubic meters
      gallons 0.003785 cubic meters
    Force      
      pounds 4.448 newtons
      kips 4,448 newtons
      kips 1,000 pounds
      Tons (short) 2,000 pounds
    Force per unit length      
      pounds per foot 14.594 newtons per meter
      kips per foot 14,594 newtons per meter
    Load per unit volume      
      pounds per cubic foot 0.15714 kilonewtons per cubic meter
    Bending moment (torque)      
      inch-pounds 0.113 newton meters
      foot-pounds 1.356 newton meters

    Stress, pressure, loading

    Force per unit area

         
      pounds per square inch 6,895 pascals
      pounds per square inch 6.895 kilopascals
      pounds per square inch 0.006895 megapascals
    Mass      
      pounds 0.4536 kilograms
    Moment of Inertia      
      inches4 416,231 millimeters4

    1.3: Calculations, Units, and Unit Conversion is shared under a CC BY license and was authored, remixed, and/or curated by LibreTexts.

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