Three negative point charges lie along a line as shown in the figure. Find the magnitude and direction of the electric field this combination of charges produces at point P, which lies 6.00 cm from the -2.00 microC charge measured perpendicular to the line connecting the three charges.
I've used the Pythagorean theorem to find the d for the outside two electric fields, E1 and E2. And I know the y components cancel out because the charges are negative and counteract. I've also converted the cm to m and the microCoulombs to Coulombs.
Here's what I have:
E1 = (8.99x10^9)(-2x10^-5)/(.06m)^2 = 4994.44 N/C
E2 = (8.99x10^9)(-5x10^-6)/(.1m)^2 = 4495000 N/C x cos 53.1 = 4.495 x 10^6
E3 = (8.99x10^9)(-5x10^-6)/(.1m)^2 = 4495000 N/C x cos 53.1 = 4.495 x 10^6
Adding up the Y vectors, I got 5.40 x 10^6; but this answer is wrong. I've been told that it needs to be some number x 10^7, but I have no idea what I'm doing wrong. Could someone please show me with steps what I'm doing wrong? It would really be helpful!