Answer: 108 m
Explanation: First the car start to move from the rest so the distance is equal to d1=a*t^2/2 = 36 m
Second, the car coast fro 2 s, it means that ir moves a constant speed
this speed is obtained from:
v=a*t = 12 m/s under this stage the d2= v* 2s= 24 m
Third the car start to stop at 1.5 m/s^2
d3= v*t-a*t^2/2 = 48 m
so the distance between signs is d1+d2+d3= 36 m + 24 m+ 48 m = 108 m
