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Homework Help: Mass of grain of sand

  1. Aug 27, 2010 #1


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    1. The problem statement, all variables and given/known data
    Fine grains of beach sand are assumed to be spheres of radius 38.1 micro meters (can't figure out the scientific sign). These grains are made of silicon dioxide which has a density of 2600 kilograms/meters^3. What is the mass in kg?

    2. Relevant equations

    3. The attempt at a solution
    I input 3 different answers and they're all wrong (603.2 kg and others near that - I know I'm way off). I'm not sure at all how to calculate. Please help!
  2. jcsd
  3. Aug 28, 2010 #2


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    Staff: Mentor

    Show how you got your answers, it is hard to help not knowing what you are doing wrong.
  4. Aug 28, 2010 #3
    Since you don't tell how you got 603.2kg, I tried guessing where you went wrong... and I guess
    that when you convert the density from kg/m3 to kg/[tex]\mu[/tex]m3, you multiplied it by 10-6 when you are supposed to multiply it by (10-6)3
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