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2.2.3)

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Given data

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Diameter d = 1.76 m

\ Velocity v = 390 km/h \ \

1km/h = (5/18) m/s

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v = 390 (5/18) m/s

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v = 108.33 m/s

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The number of revolutions made by the wheel during 36 minutes = ?

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The number of circumferences of wheel which fit inside the total distance is the number of times the wheel revolves( rev/min) in that time period.

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The number of revolutions per minute = (speed) / (circumference of wheel)

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The number of revolutions per minute  (rpm ) = v / πd

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= 108.33 / 1.76π

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= 19.602

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= 20 rpm

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It means for 1 minute wheel rotates 20 revolutions

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For 36 minute wheel rotates 20×36 revolutions.

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20×36 = 720 revolutions.

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The number of revolutions made by the wheel during 36 minutes is " 720 "

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