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De Broglie Wavelength problem

  1. Oct 17, 2008 #1
    1. The problem statement, all variables and given/known data
    A 220lb fullback runs the 40-yd dash at a speed of 19.6 ± 0.1 mi/h. What is he de Broglie wavelength (in meters)?

    2. Relevant equations
    de Broglie Wavelength: λ=h/(mu), where λ=wavelenght, h=6.626 x 10^(-34) kgm^2)/s, m=mass (kg), and u= speed

    3. The attempt at a solution
    u=19.6 m/s x (1m / 0.6214mi) x (3600s / 1h) = 113550 m/s

    m= 220lb x (0.4536kg/ 1lb) = 99.792kg

    λ= [6.626 x 10^(-34) kgm^2)/s] / [99.792kg x 113550 m/s]
    =5.847 x 10^-41 m (MY ANSWER)

    The answer in the back of the book is 7.6 x 10^-37 m
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Oct 17, 2008 #2


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    2017 Award

    1m / 0.6214mi

    This conversion is incorrect 1 km = 0.6241 miles.
  4. Oct 18, 2008 #3


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    Recheck the units here.
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