Calculate the stopping distances for a car that has an initial speed of 95 km/h with a driver's reaction time of 3.0 s for the following values of acceleration.(Reaction time is the time it takes for the driver to initially apply the breaks.)
a=-4m/s^2
a=-8m/s^2

Question

Calculate the stopping distances for a car that has an initial speed of 95 km/h with a driver's reaction time of 3.0 s for the following values of acceleration.(Reaction time is the time it takes for the driver to initially apply the breaks.) 
a=-4m/s^2
a=-8m/s^2

mihai · Answer

a speed of 95km/h in m/s that would be 95000m/3600s=26.38 m/s
reaction distance is 3*26.38=79.14m
  acc=speed/time  distance=t*speed, in this case you also add the reaction distance so d=t*s+79.14
  -4=26.38/t1 , t1=6.59s, d1=6.59*26.38+79.14=253.11m
  -8=26.38/t2, t2=3.29s, d2=3.29*26.38+79.13=165.93m