Question

Problem 3: Three charges are placed on three corners of a square, as shown in the figure below. Each side of the square is 30 cm. a. Compute the electric field at the fourth corner. b, what would be the force on a 6 μC charge placed at the vacant corner. -5uC -4 C Answers a. 2.47 x 105 N/C at 118° b. 1.48 N at 118°

Answer 1

The main concept is to be aquainted with the vector addition and having knowledge of basic formula of electrostatic.

The main concept is to be acquainted with the vector addition and having knowledge of basic formula of electrostatic. E^rightarrow at c due to - 5 mu c is E_1 = k q/r^2_BC = 9 times 10^3 times 5 times 10^- 6/(30 times 10^- 2)^2 = 5 times 10^5 N/C towards E^rightarrow at c due to - 4 mu c is E_2 = 9 times 10^9 times 4 times 10^- 6/(30 times 10^- 2)^2 = 4 times 10^5 N/C towards CD E^rightarrow at c due to 8 mu c is E_3 = 9 times 10^9 times 8 times 10^- 6/(30 squareroot times 10^- 2)^2 = 4 times 10^5 N/C towards AC Resolving E_3 E_3x = E_3 cos 45 degree = 4 times 10^5 times 1/squareroot 2 = 2.83 times 10^5 N/C E_3 y = E_3 sin 45 degree = 2.83 times 10^5 N/C so, N_c L E in x-direction E_x = E_3x - E_2 = (2.83 - 4) times 10^5 = -1.17 times 10^5 N/C Net E is Y-direction