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Buoyancy of bucket of water

  1. Apr 20, 2005 #1
    Hi I have this problem and I don't fully understand how to get started, so plz help. Thanks

    A bucket of water is accelerated upward at 2.4g. What is the buoyant force on a 3.0-kg granite rock (SG=2.7) submerged in the water? Will the rock float? Why or why not?

    I know that it would float if Fb>mg

    ...I'm just confused... plz help thanks
  2. jcsd
  3. Apr 20, 2005 #2

    Well....as a rule do rocks usually float?

    After you answer that, try imagining what it would be like to actually do this experiment. You have a bucket of water with a rock in it (either floating or not, depending on how you answered my first question). What do you have to do to make the bucket "accelerate upward"?
  4. Apr 20, 2005 #3
    the buoyant force will increase, but the "gravitational" force will increase as well. The resultang force will be proprtional to the difference between the water and rock densities, and this difference does not depend on the "gravitation".
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