A drag racer, starting from rest, speeds up for 402 m with an acceleration of +24.0 m/s2. A parachute then opens, slowing the car down with an acceleration of -6.10 m/s2. How fast is the racer moving 2.55 102 m after the parachute opens?

Answer 1

Do you mean 255 m after the parachute opens?

The velocity when the chute opens is
V1 = sqrt(2aX) = 138.9 m/s

The velocity V2 after traveling a distance X' = 255 m is calculable with V2^2 - V1^2 = 2*a*X
where a = -6.1 m/s^2 and X = 255 m