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Homework Help: Velocity of Item Falling Within A Sphere

  1. Nov 30, 2004 #1
    Is there a formula for the velocity of an item falling within a sphere of a specific material, say titanium, This is related to a problem I posted yesterday about Titanium Devouring Aliens.
  2. jcsd
  3. Nov 30, 2004 #2


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    What does being inside the sphere have to do with anything?

    (If you are wondering about the gravitational attraction of the sphere itself, shell of material has NO net gravitational attraction for anything INSIDE the sphere.)
  4. Nov 30, 2004 #3
    :mad: :mad: :mad: :mad: :mad:

    at least show some work you might have put into it
  5. Nov 30, 2004 #4

    Doc Al

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    I think PhysicsIsNotMe is talking about having a tunnel dug through a solid sphere. (Just like the hole to the center of the earth problem that has been discussed here many times.)

    You need to figure out how the gravitation field varies as you go beneath the surface of the sphere. You can then integrate to find the change in gravitational potential energy, from which you can find the KE for an object dropped into that hole as a function of distance fallen.
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