Answer: 135 m
Explanation: In order to solve this problem we have to use the kinematic equations given by:
Xf= vo-(a/2)*t^2
Vf=vo-a*t
then we have for the first case:
t=vo/a
15 m= (vo^2/)a- (a/2)*vo^2/a^2= vo^2/2a
then a = (50 km/h*(1000/3600))^2/2*15= 6.43 m/s^2
With this value of the acceleration we solve the set of equation for an initial speed of 150 km/h
xf= vo^2/2a= 150*(1000/3600)^2/(2*6.43)=135 m
