2009B2B.(modified) Three particles are arranged on coordinate axes as shown above. Particle A has charge qA=−0.20nC, and is initially on the y -axis at y=0.030m. The other two particles each have charge qB=+0.30nC and are held fixed on the x -axis at x=−0.040m and x=+0.040m, respectively.
a. Calculate the magnitude of the net electric force on particle A when it is at y=0.030m, and state its direction.
b. Particle A is then released from rest. Qualitatively describe its motion over a long time.