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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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