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- Homework Statement
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- Relevant Equations
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Here's the question ^

My first thought to solving this is to use Heisenberg's uncertainty principle. $$\Delta x \Delta p = \frac{h}{4\pi}$$ Now, we approximate ##\Delta x = \frac{L}{2}##. Then, plug and chug we end up with:$$p =\frac{h}{2\pi L}$$

I thought this was it, especially because this solution is in my physics textbooks

This is also seen from a friend's teacher's work:

However, very clearly, this is not an option. So then I considered the "standing wave" method, outline here: From 11:00 to 16:00

With this method you get $$p = \frac{h}{2L}$$

What is the correct method? What is happening? When do I use uncertainty principle and when do I treat the electron as a standing wave? Are they inconsistent?

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