Motion System Design

# Fun With Fundamentals: Problem 271

Don&#8217;t let this one run you over.

### Problem 271//Sound training

In the third installment of the Back to the Future trilogy, Doc Brown engineers a steam locomotive capable of time travel. Inspired by the design, you’ve rigged an antique locomotive going from Absecon, N.J. to Okeechobee, Fla. to try your own hand at turning back the clock.

Your train is travelling at a constant speed and approaching a tunnel, lying straight ahead. You sound a blast of the whistle and hear the return echo six seconds later. At that same instant, you sound the whistle again and hear the echo from this blast five seconds later. If the speed of sound is 1,100 ft/s, how fast is your train going? Is that fast enough to reach the 88 mph required by your flux capacitor to break the time barrier?

### Winners cirlce

Fun problem 269: Grand math slam June 2003
Total entries: 21
Number correct: 8 (.381; not a bad batting average)
Keith’s prize: Handbook of Networking & Connectivity by Gary R. McClain, AP Professional.
Handbook of Networking & Connectivity covers major aspects of designing, building, cross-connecting, and maintaining a network. Each chapter has a practical focus on real-world techniques, strategies, and guidelines to help IS professionals. The book includes standards, protocols, troubleshooting tips, and much more. Gary McClain is vice president of Internation Techvantage Group, New York. He has written and edited numerous books and articles on connectivity and network technology.

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Fun With Fundamentals: Problem 270