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Homework Help: Speed of satellite in circular orbit

  1. Sep 15, 2007 #1
    1. The problem statement, all variables and given/known data

    A satellite is in a circular orbit about the earth (M = 5.98 x 1024 kg). The period of the satellite is 9.93 x 104 s. What is the speed at which the satellite travels?

    2. Relevant equations

    v=(2*pi*r)/T

    v=sqrt((GMe)/r)

    3. The attempt at a solution

    sqrt[((6.67x10^-11)*(5.98x10^24))/r) = 2*pi*r / T
    T = 2piR^3/2 / (sqrt[GMe])
    r = 8.414 x 10^15
    v = 2*pi*r / t
    v = 5.324 x 10^11 m/s
     
  2. jcsd
  3. Sep 15, 2007 #2

    learningphysics

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    your formula looks right but I think r is wrong... check your calculations
     
  4. Sep 15, 2007 #3
    Ok after reworking I got that r = 46357704 m. So:

    v = sqrt[(GMe)/r]
    v = sqrt[(6.67x10^-11*5.98x10^24)/(46357704)]
    v = 3594.51 m/s

    But this still isn't right. Are my calculations wrong at some point?
     
  5. Sep 15, 2007 #4
    Ok I worked it again and got v = 2933.27 m/s. (Hooray human error). Can anyone verify that as correct?
     
  6. Sep 15, 2007 #5

    learningphysics

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    yes, looks right to me.
     
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