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Two electric charges q1 = 2 microC and q2 = -2 microC are located at [itex]\vec{r_1}=(1,0,0)m[/itex] and [itex]\vec{r_2}=(0,0,-1)m[/itex] respectively.

[itex] \vec{F_{12}} = \frac {1}{4\pi\epsilon_0}\frac{q_1q_2}{|\vec{r_1}-\vec{r_2}|^3}(\vec{r_1}-\vec{r_2}) [/itex]

is the formula I am using.

I get an answer of (-0.013, 0, -0.013)N but I don't think this is correct and I have no idea where I messed up.

any ideas? ( I have no numerical solutions to the questions)

I have used P = qD

q = 2x10^-6

d = (1,0,1) which I obtained from using r1-r2

So I just get the charge again multiplied by the vector

Don't think this is correct either.

Now this is confusing. The first sphere doesn't enclose any charge, so q_enclosed is just 0? And the 10m sphere encloses both, but when you find the total charge enclosed, it's 2+ (-2) = 0? so again 0?

Any help appreciated

**Calculate the force on q1 in vector form.**[itex] \vec{F_{12}} = \frac {1}{4\pi\epsilon_0}\frac{q_1q_2}{|\vec{r_1}-\vec{r_2}|^3}(\vec{r_1}-\vec{r_2}) [/itex]

is the formula I am using.

I get an answer of (-0.013, 0, -0.013)N but I don't think this is correct and I have no idea where I messed up.

any ideas? ( I have no numerical solutions to the questions)

**Calculate the electric dipole moment of this system (vector form)**I have used P = qD

q = 2x10^-6

d = (1,0,1) which I obtained from using r1-r2

So I just get the charge again multiplied by the vector

Don't think this is correct either.

**Calculate the electric fluxes through two spherical Gaussian surfaces centred at the origin with radii R1=0.5m and R2=10m respectively**Now this is confusing. The first sphere doesn't enclose any charge, so q_enclosed is just 0? And the 10m sphere encloses both, but when you find the total charge enclosed, it's 2+ (-2) = 0? so again 0?

Any help appreciated