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The Gravitational Force (between two spherical objects)

  1. Sep 27, 2005 #1
    A bowling ball (mass=7.2 kg, radius=0.11m_ and a billiard ball (mass=.38kg, radius= .082m) may each be treated as uniform spheres. What is the magnitude of the maximum gravitational force that each can exert on the other?

    I figured I was supposed to use F=Gm1m2/r^2 but I didn't know how to use the equation because the problem gave me to radii.
    Last edited: Sep 27, 2005
  2. jcsd
  3. Sep 27, 2005 #2
    if we want the maximum force, what can you say about the distance between them?
  4. Sep 27, 2005 #3
    i'm not sure, I really don't get it. I just know that I'm supposed to use r and in every other problem, they give it to me and I don't know why I have two distances.
  5. Sep 27, 2005 #4
    ok, what is r?
  6. Sep 27, 2005 #5
    I got it. I just added the radii together. Because I figured if it didn't tell me how far apart the spheres were, I had to assume they were next to eachother.
  7. Sep 27, 2005 #6
    that is the way but it is not because the question didn't give you the distance.
    maximum force means the distance is the least, this happens when they are next to each other, and that is why you add the radii together to get the r.
  8. Sep 27, 2005 #7
    awesome, thank you for your help
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