SOLUTION: A truck with 48-in.-diameter wheels is traveling at 45 mi/h. How many revolutions per minute do the wheels make? PLEASE HELP!

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Question 1008995: A truck with 48-in.-diameter wheels is traveling at 45 mi/h.
How many revolutions per minute do the wheels make?
PLEASE HELP!
Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
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A truck with 48-in.-diameter wheels is traveling at 45 mi/h.
How many revolutions per minute do the wheels make?
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1 mile = 63360 inches (see this article in Wikipedia).

The truck covers 45%2F60 = 3%2F4 miles per minute.
It is 3%2F4.63360 = 47520 inches per minute.

The circumference of the wheel is 2%2Api%2A%2848%2F2%29 = 2*3.14*24 = 150.72 inches.

Hence, the number of revolution of the wheel is 47520%2F150.72 = 315.28 per minute.