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## Homework Statement

An electric field E=141000.0i N/C causes the 4.70 g ball in the picture to hang at a α=22.9° angle. What is the charge on the ball?

## Homework Equations

E=(1/4pieE)*(q/r^2)

## The Attempt at a Solution

I tried solving this question first by drawing a force diagram on the charged particle. On the diagram:

W = T cos α -1

F = T sin α -2

I divided equation 2 by 1

I get tan α = F/mg ; since F = 1/4pie * q/r^2; i subbed it in

therefore: mgtanα4pie*r^2 = q

but i am having trouble in solving for r; i tried solving for r by using the Pythagorus theorem, but i didnt workout... I'm kinda stuck, i guess its because the known value for E field is in a component form...

can someone please guide me through this question

picture is attatched

thanks in advance.

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