Fields and Waves HELP!!!! I'm stuck on a problem on my homework assignment. A ring-shaped conductor with a radius a=2.90 cm has a total positive charge q1=0.126 nanoCoulombs uniformly distributed around it. The center of the ring is at the origin of coordinates O. What is the magnitude of the electric field at point P, which is on the positive x-axis at x=45.0 cm? I found that to be 5.56 Newtons/ Coulombs What is the direction of the electric field at point P? Positve x A particle with a charge of -2.30 microCoulombs is placed at the point P described in part (a). What is the magnitude of the force exerted by the particle on the ring? Anyone know of an equation that I can use to solve this? I tried F=(1/4*pi*epsilon_0)((q1q2/r^2) I used both x=45cm and the hypotenuse by taking the sqrt(.029^2+.45^2) and both give the same answer and its wrong. I also used E=F/q where I used 5.56 N/C and 2.3*10^-9 C and it gave me the same answer.