Question

An electron and a proton both start from rest
and from the same point in a uniform electric
field of 319.4 N/C.
How far apart are they 2.59 µs after they
are released? Ignore the attraction between
the electron and the proton. (Imagine the
experiment performed with the proton only,
and then repeat with the electron only.)
Answer in units of m

Answer 1

F=qE, so acceleration = qE/m , distance travelled = (1/2) * (acceleration) * (t^2), so u can find the distance travelled by the electron and proton seperately as you know their masses! The final seperation would be the sum of these distances!