Careful measurements have been made of Olympic sprinters in the 100-meter dash. A simple but reasonably accurate model is that a sprinter accelerates at 3.6 m/s² for 31/3 s, then runs at constant velocity to the finish line. What is the race time for a sprinter who follows this model? Express your answer using two significant figures. A sprinter could run a faster race by accelerating faster at the beginning, thus reaching top speed sooner. If a sprinter's top speed is the same as in , what acceleration would he need to run the 100-meter dash in 9.5 s ?