1953 AHSME Problems/Problem 31
Problem
The rails on a railroad are feet long. As the train passes over the point where the rails are joined, there is an audible click. The speed of the train in miles per hour is approximately the number of clicks heard in:
Solution
We assume that the clicks are heard at the head of the train. Then if the train's speed in miles per hour is , we can convert it to clicks per minute: Therefore every minute, on average, clicks are heard. The number of clicks heard in minutes is , so the number of clicks heard in minutes is equal to . In other words, the speed of the train in miles per hour is equal to the number of clicks heard in minutes, which is approximately one-third of a minute, or .
See Also
1953 AHSC (Problems • Answer Key • Resources) | ||
Preceded by Problem 30 |
Followed by Problem 32 | |
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