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

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!