Two point-charges of +8 nC and -17 nC lie on the x-axis at points x = 0 and x = +10 m, respectively. Find the electric field on the axis at point x = +5.0 m. Assume vacuum. Answer in N/C. E= k0(q./r^2) Ok, this should be pretty simple, but for some reason it's not. First, I converted the nC to C: +8E-9 and -1.7E-8. I assume the radius is +5 which would then be +25 because it's squared. K0 is 8.99*10^9, right? Then I just plugged in my values: E= -1.7E-8/25 + 8E-9/25= -3.6E-10 -3.6E-10 * 8.99E9= 3.2364 This answer is wrong though. I've tried entering it in as both a positive and negative number, but that doesn't make a difference. Where am I going wrong? This is the only way I can see to solve the problem.