Answer to Question #1482 in Electromagnetism for Jon
A negative charge of -3.0 x 10^-6 C and a positive charge of 4.0 x 10^-6 C are separated by a distance of 3mm. What is the force on the negative charge? (magnitude and direction)
Сharges with opposite signs attract each other, so the Coulomb's force would be directed to the positive charge. F = k |q1||q2|/R2 = 8.99 x109 [Nm2/C2]*|-3.0 x 10-6|[C]*|4.0 x 10-6|[C]/(3x10-3)2[m2] = 11.98 x 103 N.