An electron has an initial speed of 178000 m/s. If it undergoes an acceleration of 4.8 x 1014 m/s2, how far has it traveled before reaching a speed of 789000 m/s? Answer in units of m.

The time required to reach the higher speed is

t = (V2 - V1)/a = 611,000/4.8*10^14 = 1.27*10^-9 s

Distance traveled in that time is
(average speed) x time
= (V2 + V1)/2 * t
= [V2^2 - V1^2]/(2 a)