- #1
chris2020
- 9
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Homework Statement
can liquid helium at 4k (.1 nanometers interatomic spacing) be modeled by non spreading wave packets?
Homework Equations
1/(√2π)∫∞-∞ei(kx-wt)Φ(k)dk
W(k) was Taylor expanded to a quadratic term Δpx2/(2mħ)
The book then sas for a non expanding wave packet:
|t| << mħ/Δpx2
Another relation:
|t| Δvx =|t| Δpx/m << ħ/Δpx = Δx
The Attempt at a Solution
I'm not sure where to begin. I figure... Δx is 1×10^-10 meters
Δp>ħ/Δx
Then I could say
|t| << mΔx2/ħ
Which tell me t must be very small since we are talking about ≈ (10^-10)^2
Other then that I don't know where to go from here.