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Question
The wheel of a cart is making 5 revolutions per second. If the diameter of the wheel is 84 cm, find its speed in km per hour.
Solution
Distance covered in 1 revolution = π × d
`=(22/7xx84)"cm"`
= 264 cm
Distance covered in 1 second =(5 × 264)= π × d
= 1320
Distance covered in 1 second = (60 × 60 × 1320) cm
= 4752000 cm
`=(4752000/(1000xx100)) "km"`
= 47.52 km.
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