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Homework Help: Archimedes' Principle

  1. Nov 21, 2004 #1


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    An object is solid throuhgout. When the object is completely submerged in ethyl alcohol, its apparent weight is 15.2N. When completely submerged in water, its apparent weight is 13.7N. What is the volume of the object?

    This is my attempt:

    Weight of object in ethyl alcohol [Woe]= (density of alchohol[de])(volume of object)(gravity)

    Weight of object in water[Wow] = (densityof water[dw])(volume of object)(gravity)


    Woe/de = Wow/dw

    Woe/Wow = de/dw
    15.2/13.7 = de/dw

    but this is where i get stuck..because both the equations have volume and gravity they just cancel and i can't solve for either of the densities...

    thanks for any hints.. :confused:
  2. jcsd
  3. Nov 21, 2004 #2

    Doc Al

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    Staff: Mentor

    Apparent weight = real weight - buoyant force

    Set up two equations, one for each liquid, and compare. You'll need the density of each liquid---look them up.
  4. Nov 22, 2004 #3


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    thank you :)
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