1. PHY147 Lecture 4: Consider the electric field due to two charges. The first charge is q1 = -1.0 nC located at position (0, 0), and the second charge is q2 = -0.25 nC at position (0, 3). One unit of the coordinate system corresponds to 1 m. (a) Calculate the position where the electric field is zero and indicate it in a diagram of the (2D) coordinate system that includes the position of the charges. (b) Determine the electric field at position (1.5, 2)? (Do not forget that the electric field is a vector!) Indicate its direction in the diagram