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How many revolutions will a car wheel of diameter 22 in. make as the car travels a distance
of one mile? (Round your answer to the nearest whole number.)
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One mile = 63360 inches.
Each revolution of the car wheel moves the car forward by the circumference, which is
= = 69.1150383 inches.
The number of revolutions needed is = 916.7.
Round it to the nearest integer and get the
ANSWER. 917 revolutions (rounded).
Solved.
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In problems, where the diameter "d" of a circle is given, use the formula
C =
for the circumference.
Do not use it in the form C = , since then you must make
excessive calculation r = d/2, demonstrating your interior mental instability.
Follow the general rule : NO excessive unnecessary calculations.
Remember that they are a source of potential errors, distract your attention and take away precious time.