PHYS 1010 : concept of phyics

Two particles with charges of +5.50 nC and −8.95 nC are separated by 3.00 m.

1. a. What is the magnitude of the electrostatic force between the particles?
2. b. Is this force attractive or repulsive?

In the figure, four particles form a square. The charges are q1 = q4 = Q and q2 = q3 = q.

(a) What is Q/q if the net electrostatic force on particles 1 and 4 is zero?

The attractive electrostatic force between the point charges3.57×10-6 C and Q has a magnitude of 0.910 N when the separationbetween the charges is 7.03 m.
Find the sign and magnitude of the force Q.