One final electric field problem

1. Jan 24, 2004

eku_girl83

A ring-shaped conductor with radius a=.029 m has a total positive charge Q=1.35x10^-9 C uniformly distributed around it. The center of the ring is at the origin.
What is the electric field at point P, which is on the axis at x=.3m?
I used the equation E=(kQx)/(x^2+a^2)^3/2, but this doesn't seem to work.
Many thanks if you could help me!

2. Jan 25, 2004

himanshu121

The formula is correct might be some Arithmetic error