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Homework Help: Help with buoyancy question thanks

  1. Nov 13, 2011 #1
    help with buoyancy question thanks!!

    An object denser than water rests on the bot-
    tom of a container full of water. The object
    has volume V and a density p = 4 pw, where
    pw is the density of water.

    What supporting force N does the con-
    tainer bottom exert on the object, in terms of
    pw, g and V ?

    2. Relevant equations
    Normal force= force pressure + weight

    3. The attempt at a solution
    N = F + mg
    N = PxA + pVg
    N= ....+ 4 pwVg

    i dont know how to finish this?
    could some explain what to do now to solve for Force normal

  2. jcsd
  3. Nov 13, 2011 #2
    Re: help with buoyancy question thanks!!

    If the object is on the bottom of the container then there is definetly an upwards force on the object by the bottom of the container. There is also another force due to buoyancy.... do you know how to calculate this 'upthrust'?
    Both forces together must equal the weight of the object.
    Can you take it from there?
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