The diameter of a wheel of a bus is `90 c m` which makes 315 revolutions per minute. Determine its speed in kilometres per hour. `(T a k e\ pi=(22)/7)`

Explanation

The diameter of wheel of a bus is` 90cm`.
So,radius`=45cm`
Circumference of the circle`=2πr`
`=2×22/7×45`
`=2×22/7×45/100000`(converting in `kms`)
Now,Revolutions in per minute `=315`
So,`2×22/7×45/100000×315×60`(per minute)
`=11×9/100×9×6`
`=53.46km/hr`