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A Question on Newton's Laws

  1. Oct 14, 2008 #1
    I have got this word problem and I tried to solve but could not find the exact answer and I need the way to do it because my upcoming test has similar problems to it,,

    1. The problem statement, all variables and given/known data
    Saturnn has an equatorial radius of 6.00 * 107m and a mass of 5.67 * 1026Kg. Calculate the following:
    a) the acceleration due to gravity of Saturn.
    b) how many times greater is a person's weight on Saturn compared to that on Earth?

    2. Relevant equations
    F= mg
    Fg= Gm1m2 / r2

    3. The attempt at a solution
    I don't know where to start from because I am used to solve similar problems starting with the acceleration due to gravity which is known to be 9.81m/s2, but this only applies for Earth gravity and I don't know how to start solving this problem

    Thank you for any help
  2. jcsd
  3. Oct 14, 2008 #2


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    Staff Emeritus
    Science Advisor

    Well, you can use your second equation to derive a g for Saturn, can't you?
  4. Oct 14, 2008 #3
    I guess so , the problem is that is joined the class late, and English is not my first language
    but I will try my best

    Thank you
  5. Oct 14, 2008 #4


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    Staff Emeritus
    Science Advisor

    Sorry, my comment wasn't meant to come across as being abrupt. Perhaps I should rephrase it: how can you write your second equation so as to derive a 'g' for Saturn from it?
  6. Oct 14, 2008 #5
    Don't worry

    I will try doing it and I understand it better now

    Thank you very much
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