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Geosciences LibreTexts

Units, Conversions, and Physical Constants

  • Page ID
    11735
  • Units

    Unit Abbreviation Unit Name Quantity Base Units
    m Meter Length m
    kg Kilogram Mass kg
    Pa Pascal Pressure kg / (ms\(^2\))
    s Second Time s
    N Newton Force kgm / s\(^2\)
    K Kelvin Temperature K
    Hz Hertz Frequency 1 / s
    rad Radian Angle 1
    J Joule Energy kgm\(^2\) / s\(^2\)
    W Watt Power kgm\(^2\) / s\(^3\)
    AU or au Astronomical Unit Length See Conversions

     

    Common Conversions

    1m = 39.37 in = 3.281 ft = 1.094 yd

    1 rad = 57.30\(^\circ\)

    1\(^\circ\) = 0.01745 rad = \(\pi\) / 180

    1 Pa = 9.869 x 10\(^{-6}\) atm

    1 kg/m\(^3\) = 1000 g/cm\(^3\)

    1 AU = 1.495 x 10\(^{8}\) km = 1.495 x 10\(^{11}\) km

    1 year (yr) = 3.15 x 10\(^{7}\) s

    1 million years (my or myr) =  3.15 x 10\(^{13}\) s

    1 day = 86,400 s

    1 hour = 3600 s

    1 K = -273.15 C = -457.87 F

     

    Physical Constants

    Name Symbol Value
    Acceleration due to Gravity g 9.81 m/s\(^2\)
    Universal Gravitational Constant G 6.674 x 10\(^{-11}\) Nm\(^2\)/(kg\(^2\))
    Speed of Light c 2.98 x 10\(^{8}\) m/s
    Mass of the Sun M\(_{sun}\) 1.98 x 10\(^{30}\) kg
    Radius of the Sun R\(_{sun}\) 695700 km

    *For Planet and Moon Information see the Other Section

     

    Other

    Guide to Greek Letters: Greek Alphabet

    Power of 10 Prefixes (ex. kilo-):  Metric Prefixes

    Planetary Physical and Orbital Constants: Planets and Pluto Physical Characteristics

    Selected Moon Planetary and Orbital Constants: Moon Physical Data Note: To get M by itself, just divide the GM number by the Gravitational Constant G

    Common Formulas, Trigonometric Identities, Derivatives, and Integrals: Mathematical Formulas