Two point charges, Q1 = -6.7µC and Q2 = 1.8µC, are located between two oppositely charged parallel

Question:

Two point charges, Q1 = -6.7µC and Q2 = 1.8µC, are located between two oppositely charged parallel plates, as shown in Fig. 16-65. The two charges are separated by a distance of x = 0.47m. Assume that the electric field produced by the charged plates is uniform and equal to E = 53,000 N/C. Calculate the net electrostatic force on Q1 and give its direction.
Figure 16-65