- #1

TheBaker

- 19

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## Homework Statement

A particle is trapped in an infinite potential well, with the infinite walls at ±a. At time t=0, the wavefunction of the particle is

[tex]\psi = \frac{1}{\sqrt{2a}}[/tex]

between -a and a, and 0 otherwise.

Find the probability that the Energy of the particle is [tex]\frac{9 \bar{h}^2 \pi^2}{8ma^2}[/tex]

## Homework Equations

[tex]E_n = \frac{n^2\bar{h}^2\pi^2}{8ma}[/tex]

[tex]\psi = A \cos{\frac{(2r+1) \pi x}{2a}}[/tex] for |x| < a

[tex]\psi = 0[/tex] otherwise

## The Attempt at a Solution

I've calculated the above equations, but I'm unsure how to get from them to the probability of the particle having a certain energy. This could be really simple and it's me just having a brain dead moment, but any help would be very much appreciated.