A body that uniformly retarded comes to rest in 5.0s after travelling a distance of 10.0m. Calculate the retardation and initial velocity

Answer 1

ave vel = 10.0 m / 5.0 s = 2.0 m/s

final is zero, so initial is ... 4.0 m/s

deceleration is
... 4.0 m/s / 5.0 s = 0.80 m / s^2

Answer 2

How was the initial velocity 4.0