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Appendix D: Units and Order of Magnitude

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    145533
    • James K. Lord, Amy Richardson, Sneha Davison, and David A. Dillard
    • Virginial Tech

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    D.1 Commonly Used Orders of Magnitude

    Multiplication factor

    Prefix

    Symbol

    Example

    1012 = 1,000,000,000,000

    tera

    T

    1 terawatt = 1 TW = 1 × 1012 watts

    109 = 1,000,000,000

    giga

    G

    1 gigabyte = 1 GB = 1 × 109 bytes

    106 = 1,000,000

    mega

    M

    1 megapascal = 1 MPa = 1 × 106 pascals

    103 = 1,000

    kilo

    k

    1 kilonewton = 1 kN = 1 × 103 Newtons

    10-3 = 0.001

    milli

    m

    1 millisecond = 1 ms = 1 × 10-3 seconds

    10-6 = 0.000001

    micro

    µ

    1 micrometer = 1 µm = 1 × 10-6 meters

    10-9 = 0.000000001

    nano

    n

    1 nanovolt = 1 nV = 1 × 10-9 volts

    10-12 = 0.000000000001

    pico

    p

    1 picoamp = 1 pA = 1 × 10-12 amps

    D.2 Commonly Used Units in this Text

    Quantity

    SI Unit (symbol)

    US Unit (symbol)

    Conversion factor

    First Moment of Area (Q)

    Meters3 (m3)

    Inches3 (in.3)

    1 in.3 = 1.639 × 10-5 m3

    Second Moment of Area (I)

    Meters4 (m4)

    Inches4 (in.4)

    1 in.4 = 4.162 × 10-7 m4

    Area (A)

    Meters2 (m2)

    Inches2 (in.2)

    1 in.2 = 6.452 × 10-4 m3

    Force (F)

    Newton (N)

    Pound (lb)

    1 lb = 4.448 N

    Length (L)

    Meter (m)

    Foot (ft) or inch (in.)

    1 ft = 12 in. = 0.3048 m

    Moment of a force (M)

    Newton-meter (N·m)

    Pound-inch (lb·in.)

    1 lb·in. = 0.1130 N·m

    Power (P)

    Watt (W)

    Horsepower (hp) or lb·ft/s

    1 hp = 550 lb·ft/s = 1.356 W

    Pressure (P)

    Pascal (Pa)

    Pound per square inch (psi)

    1 psi = 6,895 Pa

    Strain (e)

    Unitless

    Unitless

    -

    Stress (s)

    Pascal (Pa) = N/m2

    Pound per square inch (psi) = lb/in.2

    1 psi = 6,895 Pa

    Temperature (T)

    °C or K

    °F or °R

    °F = (°C × 9/5) + 32

    K = 273.15 + °C

    °R = °F + 459.67

    Time (t)

    Second (s)

    Second (s)

    -

    Torque (T)

    Newton-meter (N·m)

    Pound-inch (lb·in.)

    1 lb·in. = 0.1130 N·m

    This page titled Appendix D: Units and Order of Magnitude was last modified on Fri, 30 Oct 2026 07:40:00 GMT and is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by James K. Lord, Amy Richardson, Sneha Davison, and David A. Dillard via source content that was edited to the style and standards of the LibreTexts platform.