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प्रश्न
The speed of a car is 66km per hour. If each wheel of the car is 140cm in diameter, find the number if revolution made by each wheel per minute.
उत्तर
The Circumference of Circle with diameter d is πd
The Circumference of a Circle with diameter 140cm is π x 140
= `(22)/(7) xx 140`
= 440cm
distance moved in 1 hour
= 66km
= 6600000cm
distance moved in 1 minute
= `(6600000"cm")/(60)`
= 110000cm
Number of revolutions
= `"Total distance moved"/"Circumference of Circle"`
= `(110000)/(440)`
= 250.
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