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Homework Help: Calculating mass of inner core in Kg when i only have the density

  1. Mar 23, 2010 #1
    1. The problem statement, all variables and given/known data
    SO i dont have the radius or the volume but i have an estimate of the density 14.5 10³kg m-3
    Im really uncertain of the formula needed to A. get the radius without the volume and vice versa. PLEASE HELP! Thanks in advance!

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Mar 23, 2010 #2


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    Staff: Mentor

    If density estimate is all you have, I can't think of anything. But perhaps that's not the whole question/problem?

  4. Mar 23, 2010 #3
    what else would i need? Radius? The radius is 1221km sorry for the rush in my posting and leaving out the rather important bits!
  5. Mar 23, 2010 #4


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    Science Advisor
    Homework Helper

    And the total mass, or the density of the none core part, or the overall average density.
  6. Mar 23, 2010 #5
    the question reads....

    using the information calculate the mass of the earths core in Kg applying the equation mass= density x volume.

    show all working and and include units. give answer in appropriate scientific notation and to an appropraite significant figures.

    So i have used the graph provided to get the value of density for the inner core.14.5 10³kg m-3 and the radius of 1221km. SO to calculate the volume of a sphere using these values.
  7. Mar 23, 2010 #6


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    Staff: Mentor

    So where is the problem? You have density and radius, you don't need anything else.

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