what is your final velocity after 680 meters if you start out at 90km/hr and acceleration is 9 m/s

Vo = 90 km/h * 1000 m/km * (1h/3600s) =

25 m/s.

Vf^2 = Vo^2 + 2a*d,
Vf^2 = (25)^2 + 18*680 = 12,865,
Vf = 113.4 m/s.