Three Point Charges, Two Positive and One Negative, Each Having

Multiple Choice

Three point charges, two positive and one negative, each having a magnitude of 20 μC are placed at the vertices of an equilateral triangle (30 cm on a side) . What is the magnitude of the electrostatic force on one of the positive charges?

A) 69 N
B) 40 N
C) 80 N
D) 57 N
E) 20 N