- #1
brentd49
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I have a very basic question. An electron is accelerated through a potential [tex]V[/tex], what is the velocity? Obviously, this can be solved using conservation of mechanical energy, but why am I off by a negative?
[tex]K_i + U_i = K_f + U_f [/tex]
[tex] 0 + (-qV) = \frac{1}{2} m v^2 + 0 [/tex]
[tex] v = \sqrt{-2qV/m} [/tex]
My problem must be in the initial potential energy. But I do not see how, because the potential difference is positive and the charge (electron) is negative.
[tex]K_i + U_i = K_f + U_f [/tex]
[tex] 0 + (-qV) = \frac{1}{2} m v^2 + 0 [/tex]
[tex] v = \sqrt{-2qV/m} [/tex]
My problem must be in the initial potential energy. But I do not see how, because the potential difference is positive and the charge (electron) is negative.
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