So when doing the expectation value of <p> on a stationary state we get a 0 and ive seen the standard proof showing why as well as for <p^2> not being 0. But how can momentum be 0 and(adsbygoogle = window.adsbygoogle || []).push({});

yet have a energy defined for the system? Is the energy only due to Vψ = Eψ

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# If <p> = 0 how can we know the energy of the system

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