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Homework Help: Heisenberg's uncertainty principle, find uncertainty in position

  1. Sep 30, 2011 #1
    1. The problem statement, all variables and given/known data
    Using Heisenberg's uncertainty principle, calculate the uncertainty in the position of a proton moving at a speed of (5.00±0.01) x 10^4 m/s.

    2. Relevant equations
    Δx[itex]\geq[/itex] [itex]\frac{h}{4mΔv\pi}[/itex]

    3. The attempt at a solution
    x[itex]\geq[/itex] (6.626*10^-34)/(4pi(1.6726*10^-24)(5±0.01 * 10^4)

    I get how to solve it, I just don't really understand what to do with the ±0.01. I'm assuming it's in meters, so I have to do 0.01/5 and then multiply that by 5*10^4, but I'm supposed to be getting 3*10^-10

    Thanks in advance (:
  2. jcsd
  3. Oct 1, 2011 #2
    The formula says [itex]\Delta x=\frac{h}{4\pi m\Delta v}[/itex]
    What is [itex]\Delta v[/itex]? Is it a relative or an absolute uncertainty?
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