An electron (m = 9.11 x 10^-31 kg) is accelerating in the uniform field(adsbygoogle = window.adsbygoogle || []).push({}); E(E= 1.85 x 10^4 N/C) between 2 parallel charged plates. The separation of the plates is 1.2 cm (.012 m). The electron is accelerated from rest near the negative plate and passes through a tiny hole in the positive plate.

a.What speed does it leave the hole?

b.Show that gravitational force can be ignored.

a. I know that E = F/q, where F = ma.

Given: E = 1.85 x 10^4 N/C, r (or x) = .012 m, m = 9.11 x 10^-31 kg, butwhat is q?

Using mathematical definitions, I can solve for v.

E = ma/q, where a = Eq/m

v = x/t a = v/t

a*t = x/t

t = sqrt(x/a)

Then I can plug in x and t values for v = x/t. Correct???

b. I have no idea how to carry out this proof. Need help!

Thanks.

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# Homework Help: Electric Field and electron speed

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