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Hohmann equation help

  1. Apr 16, 2009 #1
    I'm having some slight difficulties in calculating the delta-v in a hohmann transfer equation. I used the equation from wikipedia (which i hope is correct) but whenever i replace the variables i get an extremly small delta-v, is this normal???

    [tex]\Delta[/tex]v=[tex]\sqrt{}(\mu/r1)[/tex]*([tex]\sqrt{}(2*r2/(r1+r2)[/tex]-1))

    r1=6374000 meters
    r2=405500000 meters
    [tex]\mu=9.814[/tex]

    my final result was 0.00122149m/s
    it seems like a really small number, is this right or i'm i doing something really wrong?

    i attached an excel sheet to show you my work.

    thanks in advance
     

    Attached Files:

  2. jcsd
  3. Apr 16, 2009 #2

    Janus

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    The problem is your value for [itex]\mu[/itex]

    [tex]\mu = GM[/tex]

    Where G is the universal gravitational constant and is equal to

    6.67300 × 10-11 m3 kg-1 s-2

    and M in this case is the mass of the Earth, or 5.97 x 1024 kg

    so

    4.651 X [itex]10^{14}m^3 s^{-2}[/itex]
     
  4. Apr 16, 2009 #3
    thanks for that correction.
     
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