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Homework Help: Universal law of gravity

  1. Oct 4, 2007 #1
    1. The problem statement, all variables and given/known data

    Two tankers of equal mass attract eachother with a force of 3.5 x 10(to the power of 3)N. If their centres are 85m apart, what is the mass of each tanker?

    mass of 2 tankers = ?
    F= 3.5 x 10(to the power of 3)N
    r= 85m
    G = 6.67 x 10(to the power of -11) N.m(squared)/kg(squared)

    2. Relevant equations

    F = G x m1 x m2

    3. The attempt at a solution

    How do i attemp this question? Please help me.
    Last edited: Oct 4, 2007
  2. jcsd
  3. Oct 4, 2007 #2

    D H

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    Given this:

    why do you have two separate masses, m1 and m2?
  4. Oct 4, 2007 #3


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    What does that tell you about m1 and m2?
  5. Oct 4, 2007 #4
    yeah i just noticed awhile ago...so do i just sub them all the info and isolate the variable of the tank?
    Last edited: Oct 4, 2007
  6. Mar 7, 2011 #5
    step 1 since the two mases are the same you can express it as m(^2)
    step 2 rearrange the formula to get m(^2) =3.5x10(^3) x 85(^2)/6.67x10(^-11)
    step 3 square root the final answer to get the mass of the tanker and you should get 6.16x10(^8)N
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