Find the magnitude and the direction of the electric field at the thir

[Richard Ros]

Homework Statement

Two point charges are placed at two of the corners of a triangle as shown in the figure. (Take q1 = -11.3 μC, and q2 = 15.4 μC.) Find the magnitude and the direction of the electric field at the third corner of the triangle. {Correct Answer: 1.07e+07 N/C at 71.2 degrees above the -x-axis}

Homework Equations

F = ((1)/(4πε0))(q1*q2/r^2)

The Attempt at a Solution

Attached files. What am i doing wrong? I can't seem to get the correct answer.

 

[TSny]

Did you convert units correctly? Your answers appear to be off by some factors of 10.

Is E_y from q₁ positive or negative? [Edited]

 

[Richard Ros]

Hmm I don't know how I got a negative. But either way when I solve for the magnitude it'll end up being positive. Which unit should I convert? The μc or cm?

 

[TSny]

Hmm I don't know how I got a negative. But either way when I solve for the magnitude it'll end up being positive.

Yes, but the sign of E_y will affect the answer for the direction angle.

Which unit should I convert? The μc or cm?

Neither μC nor cm is an SI unit.

 

[Richard Ros]

Thanks, turns out it was just my conversion.