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

Two point charges q_{1}= 2[itex]\mu[/itex]C and q_{2}= -2[itex]\mu[/itex]C are placed at r_{1}= (3,0,0) m and r_{2}= (0,0,4)m respectively

i) What is the force of q_{1}(in vector form)?

ii) What is the electric field at the origin?

iii) What is the electric dipole moment of this arrangement (in vector form)?

iv) What is the potential energy contained in this arrangement of charges?

2. Relevant equations

F =[ k q_{1}q_{2}/ (mod (r_{1}-r_{2}) )^{3}] (r_{1}- r_{2})

E_{T}= [itex]\sum[/itex] E_{i}

E = (mod q_{i}) / 4[itex]\pi[/itex][itex]\epsilon[/itex] mod r_{i}

p = qd

U =Qq / 4[itex]\pi\epsilon[/itex] mod (r_{2}- r_{1})

3. The attempt at a solution

i) F = k [ -4x10^{-9}/ 5^{3}(3,0,-4)

= 0.288 (3,0,-4) N

ii) E_{1}= 2x10^{-9}/ 4[itex]\pi[/itex][itex]\epsilon[/itex]3

= 5.99454 i

E_{2}= 2x10^{-9}/ 4[itex]\pi[/itex][itex]\epsilon[/itex]4

= 4.49590 k

E_{T}= (6.0,0,4.5) N/C

iii) d = r_{2}- r_{1}

= (-3,0,4)

p=2x10^{-9}(-3,0,4)

= (-6x10^{-9}, 0, 8x10^{-9}) C.m

iv) U = -4x10^{-9}/4[itex]\pi[/itex][itex]\epsilon[/itex] 5 = 7.2 J

Basically, I just wanted to know if this is all right because it comes up on every single exam and I don't want to think it's right for it not to be!

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# Homework Help: Point Charges/Dipole - What is the Force/electric field/dipole moment/potential energ

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