Question

2. Two charges +3 MC and +12 m are fixed 1 m apart, with the second one to the right. Find the magnitude and direction of the net force on a -2-nC charge when placed at the following locations: (a) halfway between the two (b) half a meter to the left of the +3 IC charge (c) half a meter above the +12 MC charge in a direction perpendicular to the line joining the two fixed charges 3. Point charges q, = 50 uC and q = - 25 MC are placed 1.0 m apart. What is the force on a third charge 9, = 20 uC placed midway between q, and q,?

Answer 1

+3mc in enos filme F = off 22 + Fz) =f-k (3) x ( 21x1014 K (2) X 12 X 10-12 î = (-0.216 + 0.864) î z (0-648) Î N Magnitude of force = 0.648 N Direction of force = 0 = 0 (pom + Ve x-axis) È = -(F₃ + F12) E k ( 382 )X1012+ K(12)¥ 2x10-12 ) (0.5) 2 = (0.216 +0.096) Î = (0.312) ÎN Magnitude of force = 0.312 N Direction of force = 0 = 0 (from & Ye X -axis) 1-2 mc +3 F2 = 1 K (2) +12 12x11-12 - (0.592 = -08649 .F3 = -K (2) X3x10-2(î+o. si, (1+0.25312 = -0.0236 l - 0.01937 F = (Fi2fFz -0.03862 -0.883 h

Magnitude of force = √6.0886)²+(0.883} 0.884 N Direction of force = 0 = tant le om 10.0386) 0 = 267.5° C from eve x-axis on counterclock- nuse direction) Frosce o = tant 10.883 + 180