Particle 1 , carrying charge \(q\), particle 2 , carrying charge \(2 q\), and particle 3 , carrying charge \(-q\), are located at the vertices of an equilateral triangle of side \(\ell\) in the \(x y\) plane. Particle 1 is located at \((-\ell / 2,0)\), particle 2 is located at \((\ell / 2,0)\), and particle 3 is located on the positive \(y\) axis. Find the direction of the electric force exerted on a fourth charged particle carrying charge \(q\) located at the midpoint between particles 2 and 3 .