(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

An electron starts from one plate of a charged closely spaced (vertical) parallel plate arrangement with a velocity of 1.63x10^{4}m/s to the right. Its speed on reaching the other plate, 2.10 cm away, is 4.15x10^{4}m/s.

...

If the plates are square with an edge length of 25.4 cm, determine the charge on each.

Given and Known:

v_{i}= 1.63x10^{4}

v_{f}= 4.15x10^{4}

d = 2.10 cm

A = (25.4 cm)^{2}= (0.0645 m^{2})

m_{e}= 9.109x10^{-31}kg

q_{e}= 1.602x10^{-19}C

k = 9.00 x 10^{9}Nm^{2}/C^{2}

2. Relevant equations

a = (v_{f}-v_{i}) / (t_{f}-t_{i})

F =ma

E = F_{q}/ q

Q = EA / 4[pi]k

3. The attempt at a solution

I used:First,

F =ma, and

E = F_{q}/ q

And got:

E =ma / q

E = (2.52x10^{4}-N/C) (9.109x10^{-31}kg) / (1.602x10^{-19}C)

E = 6.823 x 10^{-6}N/C

,Then

Q = EA/4[Pi]k

Q = (6.823 x 10^{-6}N/C) (0.0645 m^{2}) / 4[Pi](9.00x10^{9}Nm^{2}/C^{2}

Q = 3.89 x 10^{4}C

So, this does not agree with the answer key's 1.13x10^{-13}C, but it seems like I'm making sensible steps toward the answer.

Guidance, please?

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# Homework Help: Determining the Charge on Parallel Plates

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