An electron enters the region of a uniform electric field between two oppositely

charged parallel plates as shown, with an initial velocity of 3 x 106 m/s. The
electric field between the plates is measured to be E = 200N/C. The horizontal
length of the plates is 10cm.
a. Find the acceleration of the electron while it is in the electric field.
( and if the electron is negativly charged, but we don't know what type it is)