(Solved): In the figure particle 1 of charge 80.0C and particle 2 of charge +40.0C are held at separat ...

In the figure particle 1 of charge $-80.0\mu \mathrm{C}$ and particle 2 of charge $+40.0\mu \mathrm{C}$ are held at separation $L=39.0\mathrm{cm}$ on an $x$ axis. What is the net electrostatic force on particle 3 , of charge $q_3=20.0\mu \mathrm{C}$, if particle 3 is placed at (a) $x=$ $78.0\mathrm{cm}$ and $(\mathrm{b})x=156.0\mathrm{cm}$ ? What should be the (c) $x$ and (d) $y$ coordinates of particle 3 if the net electrostatic force on it due to particles 1 and 2 is zero?