Electric field affecting a charged particle question

crispy_nine

At the moment I'm trying to figure out charged particle in electric field behavior and there's a type of question that seems to be confusing me lots.
Ok, here's such a question that i'm not sure about:

A virus rests on the bottom plate of oppositely charged parallel plates in the
vacuum chamber of an electron microscope. The electric field strength between
the plates is 2.00 × 105 N/C, and the bottom plate is negative. If the virus has a
mass of 1.00 × 10–15 kg and suddenly acquires a charge of –1.60 × 10–19 C, what
are its velocity and position 75.0 ms later? Do not disregard gravity.
Answer: ( y = 6.24 cm )

I was trying to apply conservation of energy but I'm not sure how to involve the time aspect. I'd appreciate any insight. Thanks

Doc Al

To find the time, start by finding the acceleration.