1. The problem statement, all variables and given/known data A plastic rod of finite length carries an uniform linear charge Q = -5 μC along the x-axis with the left edge of the rod at the origin (0,0) and its right edge at (8,0) m. All distances are measured in meters. Determine the magnitude and direction of the net electric field at a point (0,6) m, along the positive y-axis. 2. Relevant Equation λ= Q/L ∫dx/(x^2+a^2)^3/2 = x/a^2(x^2+a^2)^1/2 ∫xdx/(x^2+a^2)^3/2 = -1/(x^2+a^2)^1/2 3. The attempt at a solution If the uniform linear charge Q is positively charge then I can solve this problem but since this is negatively charge, how do I go about solving this? I am referring to the electric field, if Q is positively charged then the electric field is pointing to northwest of point P. Thanks in advance.