QUESTION: An alcohol free driver needs 0.8 s to stop after seeing an emergency. A person who has had 4 beers need 2 seconds, a person who has had five, need 3 seconds. If driving at speed of 17 m/s, find the reaction distance (after seeing emergency, the distance travelled before pressing brakes) for the all three times. What if the speed is 25 m/s. What if it is 33 m/s. so first i had to find acceleration, then the reaction time. for the non-alcoholic the acceleration is: for 25m/s acceleration = 31.25 for 33 m/s acceleration = 41.25 if i have the acceleration how do i find the distance it took to stop. And is this acceleration supposed to be negative?