Calculating Vertical Deflection of Electron in Parallel Plate Setup

[XJellieBX]

Question:
An electron with a velocity of 3.00x10^6m/s[horizontally] passes through two horizontal parallel plates, as in the attached diagram. The magnitude of the electric field between the plates is 120N/C. The plates are 4.0cm across. Edge effects are negligible.
a) Calculate the vertical deflection of the electron.

I'm not sure what I should do here and I would appreciate any help. I think it might be \epsilon=\frac{kq}{r^2}, but I'm not exactly sure. Thanks.

 

[Doc Al]

What's the force on the electron while it's between the plates? The resulting acceleration? How long does it spend between the plates?

I think it might be \epsilon=\frac{kq}{r^2}, but I'm not exactly sure.

That's an equation for the field from a point charge, which is not relevant here. You are given the field, so find the force.