Question

Review Interactive Solution 2.33 in preparation for this problem. Suppose a car is traveling at +19.8 m/s, and the driver sees a traffic light turn red. After 0.381 s has elapsed (the reaction time), the driver applies the brakes, and the car decelerates at 7.00 m/s². What is the stopping distance of the car, as measured from the point where the driver first notices the red light?

Answer 1

1 Intial vel, u = 19.8 m/sec, finalvel, veomlec, a=7m/s2 distance travelled "offer appleging brake us in v²=4²+zas. 3 s= 42/d H Ix ,= 19082)2X 7 = 28.003 m. Distance travelled during reaction in S ut = 19.80 x 0381 m = 7.544 m. Total distance S=sits2 = 28.003 + 70544 1s = 35.547 m