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Homework Help: Density help required

  1. Feb 18, 2008 #1
    Hi all,
    My problem is concerning density and how to calculate it. Basically, calculating density of a concrete cube. I've been given;

    Weight (kg) In Air - 2.345,2.340
    In Water - 1.348, 1.360

    Dimensions - Height - 1900mm
    Width - 320mm
    Depth - 180mm

    I need to calculate the Density kg/m^3

    Does it include the specific gravity etc..? I've searched google for ages but to no avail. Could it be, Weight in air/(weight in air - weight in water) to give S.G, thus 2.35...therefore a ratio 1:2.35 of water to cement. Taking density of water as 1000kg/m^3, density of concrete is 2350kg/m^3?

    Any help will be really appreciated.

  2. jcsd
  3. Feb 18, 2008 #2


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    Science Advisor
    Homework Helper

    You seem to have been given rather too much information. If you have the dimensions and the weight in air then you have the density ( simply mass / volume )
    Be carefull of the units.

    If you wanted to be really picky you could include the bouyant effects of the air - although this wouldn't be worth it given the accuracy the dimensions are quoted to.
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