University physics 1

In an experiment, a driver driving along at 15 miles per hour (22 fu/sec) is given without waning a 3. signal to apply the breaks. Tests show that the reaction time-that is the time from the signal to when UND Physics CPSL 2-3 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 fusec2. (a) Sketch the situation what is going on. (b) How far down the road from where the signal is given will the typical (average) driver stop? (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? 4. Given a block where each side is in the order of 10 cm or so. You want to figure out the volume of this block by measuring each side. Suppose the measurement uncertainties for length, width and height are AL, AW, AH . That is the measured length is like measured = LAL where L is the "true value" of length of the box. Of course, the length of the box might be slightly different depending on the where the measurement is made. But ignore this fact and assume that the length