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Hello Everyone, Happy Thanksgiving. I have physics issues. I went around the entire boundless universe in the last two days, and found out the Schrodinger forgot to develop the math for the momentum expectation value for a 2-D particle in a box. It's nowhere to be found. I am a chemistry major, and so I need help from the physics department to engineer the math to complete quantum mechanics. Can anyone help me with my marvelous discovery below? It's series of equations used as an attempt to solve the problem that I posted. Everyone's help would be greatly appreciated. Thank you.

Suppose that a particle of mass m is confined to a rectangular region between 0<x<L and 0<y<L/2 by an infinitely high potential energy function.

Calculate the expectation value p[itex]^{2}[/itex], the square of the magnitude of the momentum

p^2(x)=∫(2/L) sin(n*pi*x/L)(ih[d/dx](2/L) sin(n*pi*x/L)dx

p^2(y)=∫(4/L) sin(2n*pi*y/L)(ih[d/dx](4/L) sin(2n*pi*y/L)dy

<p^2> =p^2(x) +p^2(y)

<p^2> =1/2 +1

<p^2> =3/2

## Homework Statement

Suppose that a particle of mass m is confined to a rectangular region between 0<x<L and 0<y<L/2 by an infinitely high potential energy function.

Calculate the expectation value p[itex]^{2}[/itex], the square of the magnitude of the momentum

## Homework Equations

## The Attempt at a Solution

p^2(x)=∫(2/L) sin(n*pi*x/L)(ih[d/dx](2/L) sin(n*pi*x/L)dx

p^2(y)=∫(4/L) sin(2n*pi*y/L)(ih[d/dx](4/L) sin(2n*pi*y/L)dy

<p^2> =p^2(x) +p^2(y)

<p^2> =1/2 +1

<p^2> =3/2

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