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Homework Help: Universal Gravitation

  1. Mar 17, 2005 #1
    A 1500 kg satellite is orbiting planet earth. The period is 86400 seconds and the radius is 42200000 meters. To determine the magnitude of attractive force..... you use equation F=GM(sat)M(Earth)/R2. I know that the mass of earth is 6.0*10(exp)7 kg and the gravitational constant is 6.67*10(exp negative 11) N*m2/kg2. My answer comes out to be 3.37 *10(exp)32, which is not one of my options?
  2. jcsd
  3. Mar 17, 2005 #2
    did you account for the radius of the earth in your calculation. The distance you need to use is orbital height above erath + earths radius.


  4. Mar 17, 2005 #3


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    The mass of the Earth is not [tex]6*10^{7}kg[/tex]. It is [tex]6*10^{24}[/tex] kg.

    and don't use r2, but rather [tex]r^2[/tex], but I think you knew that already or you probably would have put 2r instead
    Last edited: Mar 17, 2005
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