1. The problem statement, all variables and given/known data A rod lies on the x-axis with one end at the origin and another at x=2. The linear charge density is given by λ(x)=C(x^(3) + 3x^(2)). Find the x-component of the electric field Ex at the origin in terms of q. 2. Relevant equations Ex = ƩdEx ||dE||= (k|dq|/r^(2)) (z/r) dq = λ dx 3. The attempt at a solution I took z = 0 since there is no z dimension. r to be 2 since the rod is 2m long. So Ex = (1/4)kq. But the answer solution says (-2/3)kq.