December 2020
Problem of the Month
Railroad Bridge Part 2
Frank is walking across a one mile long railroad bridge ignoring his mother's commands and the signs on the bridge. He has
walked 1/4 of a mile when he looks back and sees a train coming. The train is 3/4 of a mile from the beginning of the bridge.
Which way should he run?
Let F = speed of Frank and
let T = rate of the train.
Determine the answers to the following questions:
(1) What relationship between F and T would make running
(a) toward the train appropriate?
(b) away from the train appropriate?
(2) What relationship between F and T corresponds to
(a) his escaping in both directions?
(b) his escaping in neither direction?
Be complete and show your work.