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Orbital Velocity - Satellite

  1. Sep 1, 2008 #1
    1. The problem statement, all variables and given/known data

    A science group put in a satellite of mass m kg into a circular earth orbit of radius r. The orbital velocity it needs to remain in this orbit is v. They now put another satellite into a similar orbit at the same altitude. Its mass is 3 times m. What orbital velocity would it need to be given? Give reasons using mathematical reasoning.

    2. Relevant equations

    Newton's law v = 2pi x r/T

    3. The attempt at a solution

    v^2/r=G m/r^2
    Satellite 1:
    v=√(G m/r)
    Satellite 2:
    v=√(G 3m/r)
  2. jcsd
  3. Sep 1, 2008 #2

    Shooting Star

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    Homework Helper

    What does 'm' represent here? Can you derive this formula?

    When a body moves with constant v in a circular orbit, the centripetal force is constant and equal to the force due to earth's gravity on the body. Now you can deduce the correct version of the above formula using this.
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