a point particle with charge q= 4/5 uC is placed on the x-axis at x=-10cm. A second particle of charge Q is now placed on the x-axis at x = 25cm, and its found that the electric field at the origin is zero. Find Q.

2 answers

Etotal=E1+E2
0= kq1(-.1)/abs(-.1)^3 + kQ (.25)/abs(.25)^3 in vector form.

Q= q1*(.25/.1)^2
Yes, got it!

Thank you!