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Homework Help: Displacement and Density

  1. Oct 30, 2005 #1
    Heres the question:
    A 6.8-kg piece of metal displaces 1 liter of water when submerged. Calculate its density.

    So I have no idea where to begin or how the displacement relates to the density. What can you suggest? Thanks!
     
  2. jcsd
  3. Oct 30, 2005 #2
    i reallllyy need help =\
    anybody?
     
  4. Oct 30, 2005 #3
    Density equals mass divided by volume. If the object displaces 1 liter of water, then it has a volume of 1 liter. You also have to know that 1 liter = 0.001 cubic meters. The objects density is 6.8kg/0.001m^3 or 6800kg/m^3.
     
  5. Oct 30, 2005 #4
    But wasnt the weight 6.8kg?
     
  6. Oct 30, 2005 #5
    Yes the mass is 6.8kg and the volume is 1liter which is equal to 0.001m^3. The density is mass divided by volume which is 6.8kg/0.001m^3. Do 6.8 divided by 0.001 on a calculator; what answer do you get?
     
  7. Oct 30, 2005 #6

    cepheid

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    Nope, the mass was 6.8 kg. The kilogram is a unit of mass, not weight.
     
  8. Oct 30, 2005 #7
    6800...thanks!
     
  9. Oct 30, 2005 #8
    ohhhh. okay thanks a bunch!
    im such a newbie, thats all. :)
     
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