How fast was the car going when it first began to accelerate

A car, moving along a straight stretch of high- way, begins to accelerate at 0.042 m/s2. It takes the car 68.6 s to cover 1 km. How fast was the car going when it first began to accelerate? Answer in units of m/s.

d = ut + 1/2 .a . t^2

1000 = u . 68.6 + 0.5 . 0.042 . 68.6

u = 13.14 = 13.1 m/s