I was driving along at 21 , trying to change a CD and not watching where I was going. When I looked up, I found myself 46 from a railroad crossing.

I was driving along at 21 , trying to change a CD and not watching where I was going. When I looked up, I found myself 46 from a railroad crossing. And wouldn't you know it, a train moving at 30 was only 55 from the crossing. In a split second, I realized that the train was going to beat me to the crossing and that I didn't have enough distance to stop. My only hope was to accelerate enough to cross the tracks before the train arrived. If my reaction time before starting to accelerate was 0.42 , what minimum acceleration did my car need for me to be here today writing these words?