Cora is a passenger in a car traveling east along a country highway that is parallel to a railroad track and clear of any traffic. Her friend Liz is driving. They come up behind the last car of a train on the track. Initially, the train is moving a little slower than they are. For fun, Cora decides she is interested in finding out the total length of the train.

a. Describe what Cora should tell Liz about how to drive in order to find the speed of the train, and then measure the length of the train.

b. Say they find the train is moving 45 mph. Then it takes them ten minutes to pass the train (along its full length) after they speed up to 60 mph. How long is the train? For credit, please include an explanation of how you solved the problem.