The initial speed: u=54km∕h The acceleration after the brakes applies: a=−0.3m∕s2 From the equation of motion, the time period required to stop the car is, v=u+at 0=54(
5
18
)−(−0.3)t t=15s And, v2−u2=2as 0−(54×
5
18
)2=2(0.3)s s=375m The vehicle's position relative to the traffic light is, d=400−s d=400−375 d=25m