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

what is the electric field at point A (0,12) if there is charge c of 8*10^-9 coulombs at (16,0) and a charge d of 6*10^-9 coulombs at (-9,0)

determine x and y components of electric field (see diagram)

2. Relevant equations

electric field e = kq/r^2 where k is 9*10^9, q is charge, r is distance from point

3. The attempt at a solution

x components:

e_c = [(9*10^9)(8*10^-9)/(sqrt(16^2 + 12^2)^2 ]sin(phi)

= [(9*10^9)(8*10^-9)/(sqrt(16^2 + 12^2)^2 ] * [ 16 /(sqrt(16^2 + 12^2))]

= [(9*10^9)(8*10^-9)(16)] / [(16^2 + 12^2)^(3/2)]

= 0.144 newtons/coulomb

e_d = [(9*10^9)(6*10^-9)/(sqrt(9^2 + 12^2)^2 ]sin(theta)

= [(9*10^9)(6*10^-9)/(sqrt(9^2 + 12^2)^2 ] * [ 9 /(sqrt(9^2 + 12^2))]

= [(9*10^9)(6*10^-9)(9)] / [(9^2 + 12^2)^(3/2)]

= 0.144 newtons/coulomb

y components:

e_c = [(9*10^9)(8*10^-9)/(sqrt(16^2 + 12^2)^2 ]cos(phi)

= [(9*10^9)(8*10^-9)/(sqrt(16^2 + 12^2)^2 ] * [ 12 /(sqrt(16^2 + 12^2))]

= [(9*10^9)(8*10^-9)(12)] / [(16^2 + 12^2)^(3/2)]

= 0.108 newtons/coulomb

e_d = [(9*10^9)(6*10^-9)/(sqrt(9^2 + 12^2)^2 ]cos(theta)

= [(9*10^9)(6*10^-9)/(sqrt(9^2 + 12^2)^2 ] * [ 12 /(sqrt(9^2 + 12^2))]

= [(9*10^9)(6*10^-9)(12)] / [(9^2 + 12^2)^(3/2)]

= 0.192 newtons/coulomb

net electric force components:

x = 0.144+0.144 = 0.288 newtons/coulomb

y = 0.108+0.192 = 0.300 newtons/coulomb

my net components are wrong. why?

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# Homework Help: Electric field on point charge

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