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Homework Help: Satellite and gravitational force

  1. Jul 20, 2011 #1
    a 500 kg satellite experiences a gravitational force of 3000 N, while moving in a circular orbit around the earth.
    a: find the radius of the circular orbit
    b: find the speed of the satellite
    c: find the period of the orbit

    attempt

    a:
    g= GM/r^2
    r=sqrt(GM/g)
    r= 3.33 x 10^-6 m

    am i right?
     
  2. jcsd
  3. Jul 20, 2011 #2
    Think about your answer for a second... does 10^-6m make any physical sense?
     
  4. Jul 20, 2011 #3
    not at all...where did i go wrong?
     
  5. Jul 20, 2011 #4
    Your equation is missing a term for the mass of the satellite:

    [tex] F_{G} = \frac{GMm}{r^{2}} [/tex]
     
  6. Jul 20, 2011 #5
    thanks a lot!
     
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