A scanning electron microscope uses a uniform 15.0-kN/C electric field to accele

Question

A scanning electron microscope uses a uniform 15.0-kN/C electric field to accelerate electrons horizontally toward the subject to be imaged. After travelling 5.0 cm the electrons are accelerated to a speed of 1.62x107 m/s. The next step is to deflect the electrons so that they can scan across the sample—hence the scanning electron microscope. To accomplish this, the electrons are directed between a pair of oppositely charged parallel plates, which produce a uniform electric field of 6.42x103 N/C perpendicular to the electron beam. This field extends for 3.5 cm along the electron’s path.

Part A For the scanning electron microscope described above, find the electron’s vertical displacement. Express your answer to two significant figures and include the appropriate units. h = SubmitMy AnswersGive Up

Part B What would be the electron’s vertical displacement if the scanning electric field were reduced to 3.17×103 N/C ? Express your answer to two significant figures and include the appropriate units.

Explanation / Answer

Amount of time T = 3.5 * 10-2 / 1.62 * 107 = 2.16 * 10-9 s

Acceleration = E q / m = (6.42 x 103 * 1.6 * 10-19) / (9.11 * 10-31)

= 1.128 * 1015 m/s2

s = 1/2 a t2 = 1/2 * 1.128 * 1015 * (2.16 * 10-9)2

Electron’s vertical displacement = 2.630 * 10-3 m

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Acceleration = E q / m = (3.17 x 103 * 1.6 * 10-19) / (9.11 * 10-31)

= 5.57 * 1014 m/s2

s = 1/2 a t2 = 1/2 * 5.57 * 1014 * (2.16 * 10-9)2

Electron’s vertical displacement = 1.299 * 10-3 m

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