International System Units

Discussion in 'Homework Help' started by Alfa_ET, Dec 8, 2011.

  1. Alfa_ET

    Thread Starter New Member

    Feb 26, 2011
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    What is the partial derivative of pressure (bar) with respect to time?

    is it m^3/s?
     
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    If 1 bar = 100kPa where the Pascal [Pa] is the SI unit of pressure then presumably the unit for the time derivative (rate of change) of pressure is P_as^{-1}

    1 \ P_a=1 \ kgm^{-1}s^{-2}

    So presumably the unit of the time derivative of pressure in terms of the fundamental units is

    kgm^{-1}s^{-3}
     
  3. Georacer

    Moderator

    Nov 25, 2009
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    Actually, I think it is \frac{\partial P(bar)}{\partial t}=100k \cdot (-2) kgm^{-1}s^{-3}
    given that the formula for the pressure is as you say.
     
  4. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    If the question was actually about conversion between units then perhaps more succinctly

    1 \ Bars^{-1} \ <=> \ 100 \ kPas^{-1} \ <=> \ 10^5  \ kgm^{-1}s^{-3}

    I doubt the OP has any real ongoing interest in this matter.
     
  5. Georacer

    Moderator

    Nov 25, 2009
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    Now I saw the units reference. It was me who had the brain dead moment after all. Sigh...
     
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