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HNQ
3:38 AM
2
Q: Squares of operators in QM

James WirthLet $\vec{p} = p_x \hat{x} + p_y \hat{y} + p_z \hat{z}$, and also use the notation $|\vec{p}| = p$, where $p^2 = p_x^2 + p_y^2 + p_z^2$. What is the difference between the operator $\hat{p}^2 = \hat{\vec{p}} \cdot \hat{\vec{p}}$, and the operator $\widehat{p^2}$? And which one is the operator tha...

 
 
9 hours later…
HNQ
12:19 PM
2
Q: In a circuit, does a battery create electrons in which they 'inject' into the copper wire?

Faheem AzeemiAre electrons created from a battery and then 'injected' into the copper wire? If no, then does that mean that the battery looses power because the copper wire has run out of free electrons?

 

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