5. A particle with a charge of -4.00 × 10-6 C moves through a uniform electric field of 70.0 N/C directed downwards. It is moving horizontally at 12.0 cm/s exactly between two plates that are 10.0 cm apart. The particle has a mass of 0.0400 g. a. What is the net force on the particle? b. What is the acceleration of the particle? c. How long will it take to strike one of the plates?