Question

1.500 uc -2.400 uc 2. (15 points) Three charges are arranged as shown in the diagram. a. Find the electric field at point P. b. Find the electric potential at point P. c. Find the total potential energy of the charge system. 1 4.000 cm 3.000 cm 3.000 cm 4.000 cm 1.200 uC

Answer 1

15 uc -2.44 1. 246 Y E, sino e Electric field at point P: Enet = ( Ex + E, cos 6) i + (Ez - E, sino ) ģ Electric where E= 9x10°x 1.2x10-4 = 6.75 X 10' NIC (4 x 10" 2) Ej = 9x109x1.5x10' = 5.4x10" NIC (5x10^2) Ez = 9x109 x 2:4 x10-6 = 24 x 100 NIC ( 3x10-2) coso = 7 sino = 3/5 Enet - ( 6.75 + 5.489 ) x10ʻi + ( 24 – 5.493) x10^j Enct = 11.07 *10*1 + 80.76 *10'ſ | Enet i = 23-53 x 10^ Nel

0 Potential at P = U, + Ve + Uz 1:2 x 2.4x10-6 10-6 - - 9x109 ( 15 105* * *2*30* - 24.10 ) 3 x 10 4x109 15X10C 5 x 10-2 4 x 10-> = 9x109 1 0.3 *10^4 + 0.3x104 -0.8 x 10""). Vp = -18x105 v к Kay, 0/2 + a193 + , Уз Y_3 2,2 1.93 av 3 + OV, V2 + U = K 73 1-2 X -2-4*10-2 + 15x2.4 X 1012 10 4 X10 - 5x102 U K T15 X 1.2 x 10-12 3 x 10-2 0.9x10-10 - 0.576 *10-'0) -6 *10-10 - 0 - 4x109/ 0-6X10-" - 0.qxio 7.884 x 10-' ] U To 0.7884 J