(Solved): In the figure four particles form a square with edge length a=2.82102m. The charges are q1 ...

In the figure four particles form a square with edge length $$a=2.82\times 10^{?2}\mathrm{m}$$. The charges are $$q_1=q_4=1.61\times 10^{?15}\mathrm{C}$$ and $$q_2=q_3=q$$. (a) What is $$q$$ if the net electrostatic force on particle 1 is zero? (b) Is there any value of $$q$$ that makes the net electrostatic force on each of the four particles zero?