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Homework Help: Calculating energy of a geosynchronous satellite

  1. Feb 27, 2008 #1
    1. The problem statement, all variables and given/known data


    hey i was just wondering if i was on the right track here, the question is calculate the total energy(E) of a geosynchronous satelite (that orbits around a fixed spot) with a mass of 1500kg orbiting earth at a height of 325km with an orbital speed of 5000 m/s,

    2. Relevant equations

    ok i was taught that Total E = Kinetic E + Potential E, and also that Kinetic E= 1/2mV^2 and Potential E= mgH

    3. The attempt at a solution
    ok i took into account that gravity would not be 9.8 so
    i calculated what it would be Using Fg=Gm1m2/d^2 and i came up with 1.32x10^4,also note that to calculate distace i added 325km to the radius of the earth, then i plugged
    in 1/2(1500)(5000)^2 + 1.32x10^4(1500)325000 = Total E, does this seem correct? thanks
  2. jcsd
  3. Feb 27, 2008 #2


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    Remember energy is force * distance and so gravitatonal potential energy = GMm/r
  4. Feb 27, 2008 #3
    There is a problem with the question. Geosynchronous satellites do not orbit at 325 Km height. And a satellite at 325km with an orbital speed of 5000m/s will fall back to earth.
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