A 12.4 nC charge is located at position (x,y)= 1.0cm, 2.0cm
A) At what (x,y) position is the electric field -225,000i N/C?
B) At what (x,y) position is the electric field (161,000i + 80,500j) N/C?
C) At what (x,y) position is the electric field (21,600i – 28,800j) N/C?
The general formula is |E| = kq/|r|^2 ==> |r| = sqrt(kq/|E|)
To keep the formulas uncluttered, I’m going to drop the i+j notation, so, e.g., the charge location = (1,2) cm.
Since q is positive, the signs of the components of r = those of E.
For each of the three cases:
Define a and b as the x and y components respectively of vector E (e.g., for case A, a = -225000, b = 0)
|E| = sqrt(a^2+b^2) N/C
Solve for |r| using formula above
deltar (x,y) = |r|*(a, b)/|E| cm
position (x,y) = deltar+(1, 2) cm
Be careful with signs.