An electron is released from rest in a uniform electric field

[hitek131]

I need help with this question if anyone can give me an idea of what to do. Any help would be greatly appreciated.

An electron is released from rest in a uniform electric field. The electron accelerates vertically upward, traveling 4.50 m in the first 3.00 micro seconds after it is released.
What is the magnitude of the electric field?

 

[Tide]

HINT: $s = a t^2/2$