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Homework Help: Buoyancy and Density Archimedes

  1. May 10, 2012 #1
    1. The problem statement, all variables and given/known data

    1. a 300kg object is placed upon a block of ice what volume of ice is needed to keep the object fully above water.

    2. if the object density is .94gcm ^-3 what volume of the object remains above water on ice half the size.

    3. What volume of the object remains above water when the ice is fully melted.

    p(water) = 1gcm^-3
    p(ice) = 0.92 gcm^-3

    2. Relevant equations

    B = mfg
    V = m/p

    3. The attempt at a solution

    v= volume of water displaced

    (denstiy of water)1000 kg/m^3* v = 300(weight of object)+ (denstiy ice)920 kg/m^3 *v
    80 kg/m^3 v = 300
    v = 3.75 m^3

    2. ??????????

    3. 6% of the object remains above water because buoyancy is .94 and water is 1??????

    V = m/p

    p = 0.94 g/cm3
    M = 300 kg = 300000g
    V = 0.31914893617021 m^3

    V above water = .01914m^3

    I'm fairly sure i've got question 3 all wrong though :(
    Last edited: May 10, 2012
  2. jcsd
  3. May 10, 2012 #2
    Please respond.
  4. May 11, 2012 #3


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    Homework Helper

    No, it is correct. V(immersed)ρ(water)=mass of object

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