The diamerer of a wheel of a bus is 90 cm which makes 315 revolutions per minute. Determine its speed in kilometres per hour. (Take π=22/7)
Diameter of wheel = 90 cm
Perimeter of wheel = 2πd
Perimeter of wheel = 
Perimeter of wheel = 282.857 cm
Distance covered in 315 revolutions = 282.857× 315 = 89099.955cm
One km = 100000 cm
Distance covered = 
Speed in km per hour = 0.89 × 60 = 53.4 km per hour
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