Answer:
5 hours 12 seconds
Step-by-step explanation:
For the entire train to pass the person, the head of the lead wagon must travel (9·16 m) in 12 seconds. It is traveling at a speed of ...
(9·16 m)/(12 s) = (144/12) m/s = 12 m/s
For the train to travel 216 km + 144 m = 216,144 m will take ...
(216,144 m)/(12 m/s) = 18,012 s = 5 hours 12 seconds
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<em>Comment on the speed</em>
The speed of this "wagon train" is about 26.8 miles per hour, faster than any human and most animals can run for long periods. The Pony Express cross-country mail delivery service maybe set a reasonable standard for cross-country travel. Its average speed was about 10 miles per hour.
