(adsbygoogle = window.adsbygoogle || []).push({}); (a)In the infinite one-dimensional well, what is [tex]p_{av}[/tex]?

(b)What is [tex](p^2)_{av}[/tex]?

(c)What is [tex]\Delta p = \sqrt{(p^2)_av - (p_av)^2}[/tex]?

(d)Compute [tex]\Delta p \Delta x[/tex], and compare with the Heisenberg uncertainty relationship.

Here's my working:

(a)[tex]p_{av}=0[/tex].

I'm not so sure about this bit

(b)[tex](\frac{p^2}{2m})_{av} = E_{n} = \frac{\hbar^2\pi^2n^2}{2mL^2}[/tex].

There fore [tex](p^2)_{av}=(\frac{\hbar\pi^2n^2}{L})^2[/tex]

(c)Therefore,

[tex]\Delta p = \frac{\hbar\pi n}{L}[/tex].

(d)[tex]\Delta p\Delta x = \frac{\hbar}{2}\sqrt{2n^2\pi^2 -1}[/tex]

Part (d) it seems the most suspicious, that is, the uncertainty increases with n^2. Have I done anything wrong?

**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!

# Homework Help: A momentum problem

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