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Finding the density of a hydrogen proton

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

    A proton, which is the nucleus of a hydrogen atom, can be modeled as a sphere with a diameter of 2.4 fm and a mass of 1.67e-27 kg. Determine the density of the proton.

    2. Relevant equations

    As far as I know, the only required formula is D = m/v

    3. The attempt at a solution

    Well my attempt looks like this:

    (2.4)^3*pi*(4/3) = 57.90583579 fm^3

    Used google to convert that into kilometers, and got 57.905835791 (femtometer^3) = 5.79058358e-44 meter^3.

    Divided 1.67e-27 kg by 5.79058358e-44 meter^3.

    Got 2.883992566e16 but apparently, it's wrong.

    Any suggestions guys?
  2. jcsd
  3. Sep 1, 2012 #2


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    Hello, AryRezvani.

    Note they give you the diameter, not the radius of the proton.
  4. Sep 1, 2012 #3
    Ahh...... Feeling rather stupid now.

  5. Sep 1, 2012 #4


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    That's not stupid, just a little oversight...(I'm doing things like that a lot in my old age :redface:).
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