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Question
The diameter of a wheel is 1.4m. How many revolutions does make in moving a distance of 2.2km?
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Solution
The Circumference of a Circle with diameter d is πd
The Circumference of a Circle with diameter 1.4m is π x 1.4
= `(22)/(7) xx 1.4`
= 22 x 0.2
= 4.4m
Total distance moved
= 2.2km
= 2.2 x 1000m
= 2200m
Number of revolutions
= `"Total distance moved"/"Circumference of Circle"`
= `(2200)/(4.4)`
= 500.
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