(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Consider a particle in a one dimensional box of length L, whose potential energy is V(x)=0 for 0<x<L, and infinite otherwise.Given the wave function at ground state ψ=sqrt(2/L)sin (pi*x/L) Compute ΔxΔp where

2. Relevant equations

Δx=sqrt(<x^2>-<x>^2) and Δp=sqrt(<p^2>-<p>^2)

3. The attempt at a solution

I have set the expected value for as <x^2> equal to the integral from 0 to L ψ1(x)(x^2)ψ1(x)dx, as done by my prof. I then evaluated this to 2/L*the integral from 0 to L x^2sin^2(pi*x/L)dx. However I am stuck here, and my prof's solution goes straight to L^2(1/3-1/2pi^2). I am confused as to how he evaluated this integral and the role of (x^2) in the equation, if steps could be shown that would help immensely, also when calculating <x>, is x included in the integral, and how might it be evaluated if included with sin^2(pi*x/L). Thanks in advance.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Computing Heisenberg Uncertainty Value

**Physics Forums | Science Articles, Homework Help, Discussion**