Stu Hears That Whistle ABlowing....
Although warned of the danger numerous times, Stu Dent always walked across the railroad bridge on his way to school. One day, Stu was onefourth of the way across the bridge when he heard a train approaching from behind him. It was exactly one bridgelength away from him. Which direction should he run...back or forward?
Note: Could you generalize your solution for the case where Stu is 1/nth of the way across the bridge?
Hint: Use d = rt to set up two equations, one for each direction he could run.
Solution Commentary: Suppose B = length of bridge, R = rate of train, XT = Stu's speed needed to escape running towards the train, and AT = Stu's speed needed to escape running away from the train.
Then, if Stu runs towards the train, (B/4)/XT = (3B/4)/S.
And, if Stu runs away from the train, (3B/4)/AT = (7B/4)/S.
Then.....
