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

Question

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)

Answer 1

a. Acceleration is
a = e*E/m

e is the electron charge and m is the electron mass

b. Solve the equation

Since the electron's velocity component parallel to the plates remains the same as when it entered,
t = 0.10 m/(3*10^6 m/s)

Answer 2

how do we find out the electron charge and mass if we don't know what type it is?

Answer 3

sorry but that didn't really give me the answer because we don't know the electron mass or type??