f= -72.1

-53.0 x 10-6 C
91
Find the net force on 93.
+105 x 10-6 C
+
92
0.50 m
0.95 m
-88.0 x 10-6 C
93
F₁ = force exerted on 93 by 91
F₂ = force exerted on 93 by 92
F₂ = -92.0 N
F₁ = = 19.9 N
ΣF=[?]N
Remember: Forces pointing left are negative (-);
forces pointing right are positive (+).