Gold versus Silver

  1. I am not an engineer so I was wondering if a pound of gold can ever weigh more than a pound of silver under any circumstances relative to the universe as a whole?

    John
     
  2. jcsd
  3. russ_watters

    Staff: Mentor

    The question doesn't make sense. A pound is a pound is a pound. They are all equal. But "relative to the universe as a whole" has no meaning I can discern.
     
  4. SteamKing

    SteamKing 8,565
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    It depends upon which 'pound' unit you are using.

    Pounds avoirdupois consist of 7000 grains or approx. 453.6 g
    Pounds troy consist of 5760 grains or approx. 373.2 g

    1 pound avoirdupois is also divided into 16 ounces, while the troy pound is divided into 12 troy ounces.

    When quoting the price of a precious metal like gold, the amount is always for 1 troy ounce.
     
  5. There is much more stuff. If you are talking a bout the rest mass it will not change as far as we know, but there is also the relativistic mass, and then there is weight (the gravitational force on a planet) So in a way the question is one of language and not of physics.
     
  6. I was thinking in the terms of Dimensionless Numbers when posting question.

    John
     
  7. Astronuc

    Staff: Mentor

    Let us assume in the context of the OP, that one uses the same unit of mass in the same inertial frame in the same gravitational field. Then a pound is a pound as Russ mentioned. The number of moles (atoms) will be different and volumes will be different.

    Silver has an atomic weight (mass) of 107.87 amu and density of 10490 kg/m3, and gold has an atomic mass of 196.97 amu and density of 19300 kg/m3. The density is reported at room temperature and 1 atm pressure.
     
  8. The short answer is no since the measure 1 pound mass is almost independent of the material considered and quite independent for practical purposes.

    However

    The weight of a 1 pound mass is a measure of the force of attraction of gravity, which in turn is the aggregated sum of the forces of attraction of all the particles.
    Now it is entirely conceivable that one pound mass of rarified gas in a tall thin column might aggregate to less attractive force than a flat, consolidated lump of gold because the upper particles are further away and therefore subject to a smaller force of attraction in the gas column.
    However you have specified gold and silver which will make very similar lumps.

    The other issue is whether you can fit an exact number of atoms of either into one pound mass.
    So if you wish to measure the quantity of gold or silver by whole numbers of atoms then yes the gold will weigh more.
    Further both metals have isotopes that would change these weights slightly if included.
     
    Last edited: Jan 4, 2013
  9. SteamKing

    SteamKing 8,565
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    Which weighs more? A pound of lead or a pound of feathers?
     
  10. D H

    Staff: Mentor

    You are off topic because gold and silver are both precious metals. Stop. Now.


    Yes. A pound of gold at the center of the Earth weighs nothing, more or less. An avoirdupois pound of silver at the mantle-core boundary weighs more than a pound (pound force).

    This makes no sense, so I ignored this part of your question.
     

  11. Just speculating that on other planets weights of elements could be different.
     
  12. D H

    Staff: Mentor

    No.

    Read our rules on posting "personal theories or speculations that go beyond or counter to generally-accepted science."

    Thread locked.
     
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