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Homework Help: Shouldn't be a tough problem to solve

  1. Aug 23, 2004 #1
    I just had my first college physics class today, and already I'm stuck on the first problem. I already had physics in HS and I expected I wouldn't have that much trouble in college. So here is a question that I have no clue how to answer.

    A crystalline solid consists of atoms stacked up in a repeating lattice structure. Consider a crystal as shown in figure p1. The atoms reside at the corners of the cubes of side L = 0.200 nm. One piece of evidence for the regular arrangement of atoms comes from the flat surfaces along which a crystal separates, or cleaves, when it is broken. Suppose this crystal cleaves along a face diagonal as in p2. Calculate the spacing d between two adjacent atomic planes that separate when the crystal cleaves.

    (the pictures are in 3d)

    OOOOOOOO
    OOOOOOOO
    OOOOOOOO
    l<-L->l \d\



    OO OOOOOO
    OOO OOOOO
    OOOO OOOO



    the answer is .141 nm

    so if anyone would help me out with this i would greatly appreciate it
     
  2. jcsd
  3. Aug 25, 2004 #2

    ehild

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    Well, maybe my picture helps.

    ehild
     
    Last edited: Jun 29, 2010
  4. Aug 25, 2004 #3

    JasonRox

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    Yeah, that picture is helpful.
     
  5. Aug 25, 2004 #4
    Just use the Pythagorean theorem :cool:
     
  6. Aug 25, 2004 #5
    Ya I had no clue how the pythagorean theorm was to be used when i read the problem. Thanks for the post and that nice diagram though. Doesn't seem tough any more. :cool:
     
  7. Aug 26, 2004 #6

    ehild

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    It's a pleasure ... :smile:

    ehild
     
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