Physics

Physics

Problem

Two point charges are placed in the xyxy-plane as follows: Charge q1=+5 μCq_1 = +5\,\mu\text{C} is fixed at the origin (0,0)(0,0) and charge q2=−3 μCq_2 = -3\,\mu\text{C} is fixed at the point (0, 0.30 m)(0,\,0.30\,\text{m}). A point PP is located at (0.40 m, 0)(0.40\,\text{m},\,0). (i) Calculate the magnitude of the electric field at PP due to q1q_1. (ii) Calculate the magnitude of the electric field at PP due to q2q_2. (iii) Determine the magnitude and direction of the net electric field at PP produced by the two charges.
Intuitive explanation

Electric field is the force per unit charge that a point charge creates in the space around it. The key insight is that you must treat each charge's field separately using E=k∣q∣/r2E = k|q|/r^2, then combine them as vectors—paying careful attention to direction (fields point away from positive charges and toward negative charges). Once you have both field vectors, add them component-wise to find the net field's magnitude and angle.

Intuitive explanation

Electric field is the force per unit charge that a point charge creates in the space around it. The key insight is that you must treat each charge's field separately using E=k∣q∣/r2E = k|q|/r^2, then combine them as vectors—paying careful attention to direction (fields point away from positive charges and toward negative charges). Once you have both field vectors, add them component-wise to find the net field's magnitude and angle.

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