Answered by AI, Verified by Human Experts
Before the driver applies the brakes ( with the reaction time ):d 1 = v0 · t = 20 m/s · 0.53 s =10.6 mAfter that:v = v0 - a · t10 = 20 m/s - 7 · t17 · t1 = 20t1 = 2.86 sd 2 = v 0 · t1 - a · t1² / 2d 2 = 20 m/s · 2.86 s - 7 m/s² · (2.86 s)²/2 = 57.2 m - 28.6 m =28.6 md = d 1 + d 2 = 10.6 m + 28.6 m =39.2 mAnswer:the stopping distance of a car is 39.2 m....