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Homework Help: Law of universal gravitation (am I doing it wrong)

  1. Jan 6, 2015 #1
    1. The problem statement, all variables and given/known data
    What is the gravitational force between Earth and the sun if the Earth has a mass of 5.98 x 10^24 and the sun has a mass of 1.99 x 10^30. The r is (1.5 x 10^11)^2

    2. Relevant equations

    G= 6.67 x 10^-11 N m^2 /kg^2 ( note that this is a constant)

    3. The attempt at a solution
    I simply plugged in, and gathered the like terms and put them together accordingly so i got [( 6.67)(5.98)(1.99)]/(1.5)^2=35.277 ... Then you would move the decimal to get 3.52

    Next i got all the exponent so( i canceled out the ten) -11+30+24-22= 21

    so I got 3.52 x 10^21 N but the answer key said it is 3.52 x 10^22 N

    What did I miss or is it a typo?
    Last edited: Jan 6, 2015
  2. jcsd
  3. Jan 6, 2015 #2


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    You really want to take another look at this number.
  4. Jan 6, 2015 #3
    I meant 1.5 x 10 ^11 (sorry)
  5. Jan 6, 2015 #4


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    And what did you do with the factor of 10 you removed in the process?
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