An electron is accelerated through a uniform electric field of magnitude 2.5x10^2 N/C with an initial speed of 1.2x10^6 m/s parallel to the electric field.

a) Calculate the work done on the electron by the field when the electron has travelled 2.5 cm in the field.
b) Calculate the speed of the electron after it has travelled 2.5 cm in the field.
c) If the direction of the electric field is reversed, how far will the electron move into the field before coming to rest?

2 answers

Please, please, please, this is the first question of many and I don't get it.
An electron is projected with an initial speed v0 = 1.60 × 106m/s into the uniform field
between two parallel plates as shown below. Assume that the field between the plates is
uniform and directed vertically downward, and that the field outside the plates is zero. The
electron enters the field at a point midway between the plates