# Heisenberg's uncertainty principle, find uncertainty in position

1. Sep 30, 2011

### Glissando

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$\geq$ $\frac{h}{4mΔv\pi}$

3. The attempt at a solution
x$\geq$ (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. Oct 1, 2011

### DiracRules

The formula says $\Delta x=\frac{h}{4\pi m\Delta v}$
What is $\Delta v$? Is it a relative or an absolute uncertainty?

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