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Homework Help: Law of Gravitation

  1. Jan 23, 2010 #1
    1. The problem statement, all variables and given/known data

    An astronaut weighs 8.00 × 102 newtons on the
    surface of Earth. What is the weight of the
    astronaut 6.37 × 106 meters above the surface of
    Earth?
    (1) 0.00 N (3) 1.60 × 103 N
    (2) 2.00 × 102N (4) 3.20 × 103 N

    2. Relevant equations
    Gm1m2/r^2


    3. The attempt at a solution
    When I used my calculator it gave a completely different answer... am guessing I used the wrong formular, which should I use?
     
  2. jcsd
  3. Jan 23, 2010 #2

    mgb_phys

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    Science Advisor
    Homework Helper

    Thats the correct formula but I suspect you are using it wrongly.
    The r^2 says that the force decreases as the square of the distance from the centre of the earth

    What are the distances in the two cases?
     
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