A car moving along a straight highway with a 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?
u=126 km/h=126×185m/s=35m/s v=0 s=200m Newton's Equation of motion v2−u2=2as 02−352=2a(200) a=−3.0625m/s2 Also v=u+at 0=35−3.06t t=11.4s
