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Homework Help: Net gravitational force problem in a straight line?

  1. Oct 20, 2005 #1
    Question

    In the figure attached, what is the magnitude of the net gravitational force exerted on the 0.100-kg uniform sphere by the other two uniform spheres? The centers of all three spheres are on the same line.

    So, I'm thinking [tex]F_1=(Gm_1m_2/r_1^2)[/tex] and [tex]F_2=Gm_1m_3/r_2^2[/tex].

    [tex]F_1=(6.673*10^-10)(.100)(10.0)/(.600^2)[/tex]
    [tex]F_2=(6.673*10^-10)(.100)(5.00)/(.400^2)[/tex]

    [tex]F_1=1.854*10^-10[/tex]
    [tex]F_2=-2.085*10^-10[/tex]

    [tex]F_x=F_1+F_2=-2.31*10^-11[/tex] N

    I don't think there is a force in the y-direction, so [tex]F=\sqrt(F_x^2)=2.31*10^-11[/tex] N.

    Is this correct?
     

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    Last edited: Oct 20, 2005
  2. jcsd
  3. Oct 20, 2005 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Looks good to me. (You did have a few typos in some of your steps.)
     
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