University physics 1

3. In an experiment, a driver driving along at 15 miles per hour (22 ft/sec) is given without waning a signal to apply the breaks. Tests show that the reaction time-that is the time from the signal to when Nature of Measurement Uncertainty the breaks lock-has a mean value of .68 seconds and an rms of .25 sec. Assume that the road conditions are such that the frictional acceleration with breaks locked comes out - 20 ft/sec?. (a) Sketch the situation what is going ony - 20 ft / sec ? frictional acceleration of bre (b) How far down the road from where the signal is given will the typical (average) driver stop? 22ft - 685x = 14.96 Ff S/c (c) Between about what two distances down the road will 68% of the drivers stop? (d) If you needed to figure out a distance dmax down the road such that about 95% of a random sample of drivers in these conditions could stop before reaching the distance dmax, what would you estimate for dmax