Given the following, what is the net force on the particle? What is the acceleration of the particle? How long will it take to strike one of the plates?

A particle with a charge of -4.00 x 10^-6 C4.00x106C moves through a uniform electric field of 70.0 N/C70.0NC directed downwards. It is moving horizontally at 12.0 cm/s12.0cms exactly between two plates that are 10.0 cm10.0cm apart. The particle has a mass of 0.0400 g0.0400g.