Question

ints he dectie feld Using unit vector notation, write an expression for the electric field at a point P located at (2.2m, 1.0m) due to charges q1 +20pC and q,--20μC located at (-1.3m, 0.5 m) and (1.1m, -2.5m), respectively. Write a second expression for the force this field would exert on a charge of +1.0nC located at point P. 亡 a. +10ACて ra.

Answer 1

Pat (2.2 m, 1.0 m) q_1 = 20 m c at (- 1.3 m, 0.5 m) q_2 = -20 m c at (1-1 m, - 2.5 m) The distance between p from q_1 Is r_1 squareroot (x -x_1)^2 + (y - y_1)^2 r_1 = squareroot (2.2 m - (- 1.3 m)^2 + (1.0 m - 0.5 m)62 r_1 = 3.53 55 m theta_1 = tan^-1 (y - y_1/x - x_1) = Tan^-1 (1.0 m - 0.5 m/2.2 m - (- 1.3 m) theta_1 = 8.13 degrees the distance between p from t_2 is r_2 = squarerrot (x - x_2)^2 + (y - y_2)^2 r_2 = squareroot (2.2 m - 1.1 m)^2 + (1.0 m - (- 2 - 5 m)^2 r_2 = 3.669 m theta_2 = tan^-1 (y - y_2/x - x_2) = tan^-1 (1.0 m - (- 2.5 m)/2.2 m - 1. 1m) theta = 72.55 degrees the net electric field at point p is E = 9 k E_1/r^2 times [cos theta i^+ sin theta j^] + k e_2/r_2^2 r [cos theta_2 i