A Point Charge Q Is Placed on the X Axis $\mu$

Multiple Choice

A point charge Q is placed on the x axis at x = 2.0 m.A second point charge,-Q,is placed at x = 3.0 m.If Q = 40 $\mu$ C,what is the magnitude of the electrostatic force on a 30- $\mu$ C charge placed at the origin?

A) 7.2 N
B) 3.9 N
C) 1.5 N
D) 14 N
E) 8.1 N