Car b is traveling a distance d ahead of car a. both cars are traveling at 60 ft/s when the driver of b suddenly applies the brakes, causing his car to decelerate at 12 ft/s. it takes the driver of car a 0.75 s to react (this is the normal reaction time for drivers). when he applies his brakes, i dece lerates at 15 ft/s. determine the minimum distance d be tween the cars so as to avoid a collision