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Homework Help: Satelites And Orbits

  1. Nov 5, 2007 #1
    1. The problem statement, all variables and given/known data

    A satelite is placed in orbit 6.00x10^5 meters above the surface of Jupiter which has a mass of 1.90x10^27kg and has a radius of 7.14x10^7m. Find the orbital speed of the satelite

    2. Relevant equations


    3. The attempt at a solution

    First i added the altitude of the satelite to the radius of Jupiter to find the total orbital radius, then just plugged in numbers to get:


    That seems like it would be right but my answer is way too big

    Any help would be greatly appreciated
  2. jcsd
  3. Nov 5, 2007 #2
    A common mistake in these problems is to forget the square root.

    Is that what you did?

    The answer I got was reasonable using your method.
  4. Nov 5, 2007 #3
    lol this time i got 4.2x10^4m/s which is the right answer. Maybe i did forget the squre root.

    I had one more question and it is:
    Suppose the surface of a space station is rotating and 35.8m/s. What must be the value of r (radius) for the astronauts to weigh one-half their weight on earth.

    I was able to get two equations equal to each other and they are M(V^2/r)=M(g)
    Then i rearranged to get V^2/r=1/2g-----> i divided "g" by two because of the half weight thing
    but when i solve for r its a super small number
    where am i going wrong?
  5. Nov 5, 2007 #4
    It seems right to me....... re-check your solving for r.

    Did you remember to square the velocity? :)

    What do you mean by "super small number"?
  6. Nov 5, 2007 #5
    gah i made another stupid mistake
    i did (1/2g)/V^2 for some reason
    i have the right answer now though
    lol im having an off night
    thansk tough
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