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Question
The diameters of the front and rear wheels of a tractor are 80 cm and 2 m respectively. Find the number of revolutions that a rear wheel makes to cover the distance which the front wheel covers is 800 revolutions.
Solution
Radius of the front wheel = 40 cm = 2/5 m
Circumference of the front wheel `= (2pixx2/5)"m" = (4pi)/5 "m"`
Distance covered by the front wheel in 800 revolutions `=((4pi)/5 xx800)"m" = (640pi)"m"`
Radius of the rear wheel = 1 m
Circumference of the rear wheel `= (2pixx1) =2pi "m" `
∴ Required number of revolutions `"=Distance covered by the front wheel in 800 revolutions"/"Circumference of the rear wheel"`
`= (640pi)/(2pi)`
= 320
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