A simple and common technique for accelerating electrons is shown in Figure 18.51, where there is a uniform electric field between two plates. Electrons are released, usually from a hot filament, near the negative plate, and there is a small hole in the positive plate that allows the electrons to continue moving.

(a) Calculate the acceleration of the electron if the field strength is 2.50 x 10⁴ N/C.

(b) Explain why the electron will not be pulled back to the positive plate once it moves through the hole.

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