Conditions for quantised or continuous energies

AI Thread Summary
For a particle in a potential V(x), continuous energies occur when V(x) is zero, indicating a free particle. Quantised energies arise in scenarios like an infinite potential well, where the particle is confined. A potential that allows both continuous and quantised energies could be a finite square well, where the particle has quantised energy levels inside the well and continuous energies outside. This occurs because the particle is confined within the well but can escape to a continuum of states beyond the potential barrier. Understanding these conditions helps clarify the relationship between potential shapes and energy quantization.
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Homework Statement



For a particle moving in a potential V(x), what are plausible forms of V(x) that give:

(i) entirely continuous,

(ii)entirely quantised

(iii) both continuous and quantised

energies of the particle? Sketch, with justification, the forms of V(x) for each of these 3 cases.


Homework Equations





The Attempt at a Solution



(i) when the particle is free (V(x) is zero), the particles energies are continuous.

(ii) When the particle is in an infinite potential well, the energies are quantised.

(iii) I have no idea about this one. Can anyone help?
 
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How about a square well whose sides have finite potential instead of infinite? Can you explain why that would work?
 
So it would have quantised energy inside the well (since it's confined) and continuous energies outside the well?
 
If you mean by 'in' that it has energy less than the wall energy, yes.
 
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