Q 3.6 A car moving along a straight highway with speed of 126 km h-1 is brought to a stop within a distance of 200 m. What is the retardation of the car (assumed uniform), and how long does it take for the car to stop ?
Initial velocity(u)=126 km h-1=35 m s-1
Distance travelled before coming to rest(s)=200m
Using the third equation of motion
Using the first equation of motion
The retardation of the car is 3.0625 m s-2 and it takes 11.428 seconds for the car to stop.