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Homework Help: De-Broglie waves

  1. Aug 10, 2008 #1
    1. The problem statement, all variables and given/known data
    A proton is accelerated from rest through a potential of 1kV. Find its de Broglie wavelength.

    2. Relevant equations
    [tex]\lambda=h/p[/tex]


    3. The attempt at a solution
    I tried to get p (momentum) by energy comparison:

    e*1000=0.5*m*v^2
    v=437 621.130 016 524 m/s

    which doesn't makes sense... what am I doing wrong?
     
  2. jcsd
  3. Aug 10, 2008 #2

    nicksauce

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    Science Advisor
    Homework Helper

    Do you mean 437621.130016524 m/s? Or 437,621,130,016,524 m/s? If the first, then that is roughly what I get when using google calculator (but why so many places after the decimal??), why doesn't it make sense to you? If the second, then that indeed doesn't make sense ,and I would recommend trying to put in the numbers again.
     
  4. Aug 10, 2008 #3
    Oh snap!
    It didn't make sense since I used planck constant with eV*s units all the time instead of J*s units... :grumpy:

    Thanks nicksauce.
     
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