Problem:
On a dark and stormy night Snoopy suddenly saw a flash of lightning. Ten seconds later he heard the sound of thunder. The speed of sound is feet per second and one mile is feet. Estimate, to the nearest halfmile, how far Snoopy was from the flash of lightning.
Answer Choices:
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Solution:
Use the formula (distance equals rate times time): feet per second seconds feet, which is just feet more than two miles. Therefore, Snoopy is just about two miles from the flash of lightning.
Since this is an estimate, round the speed of sound down to feet per second and the length of a mile down to feet. Then seconds per mile, so in seconds the sound will travel about miles.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions