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

An electron (e) is to be released from rest on the central axis of a uniformly charged disk of radius R. The surface charge density on the disk is +3.50 µC/m2.

(a) What is the magnitude of the electron's initial acceleration if it is released at a distance R from the center of the disk?

(b) What is the magnitude if it is released at a distance R/100 from the center?

(c) What is the magnitude if it is released at a distance R/1000 from the center?

2. Relevant equations

[tex]

E(z,R)=\frac{\sigma}{2\epsilon_{0}}\left(1-\frac{z}{\sqrt{z^{2}+R^{2}}}\right)

[/tex]

3. The attempt at a solution

So I understand that the acceleration will increase slightly as I get closer to the disk. What I cannot figure out is exactly how R and Fractions of R affect the magnitude of the Electric field. I tried to assume that z=R which allowed me to say that for:

a) I showed that the R term turns into (1-(1/sqrt(2)))

Beyond that, I cannot figure out how to go about b) and c) and my online prof just keeps telling me to look at examples in the book....

Please help!

Thank You!

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# Homework Help: Electron and Uniformly Charged Disk

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