$.$ There are two parallel plates separated by a distance D $=5$ cm$.$ One plate is held at a negative potential and the other plate is held at a positive potential, such that the potential difference between them is $.$ An electron of mass, $,$ and charge, $,$ is released from the negative plate and accelerates toward the positive plate.$$

a$.$ Write an expression for the increase in kinetic energy of the electron as it moves from the negative plate to the positive plate. $(10$ points$)$

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b$.$ If the electron starts out at rest on the negative plate, how fast is the electron moving when it reaches the positive plate? $(5$ points$)$

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