Question

The radius of the wheel of a vehicle is 42 cm. How many revolutions will it complete in a 19.8-km-long journey?

Answer 1

Radius of the wheel = 42 cm

Circumference of the wheel = 2πr

`= 2 xx 22/7xx420`

= 264 cm

`=264/100  "m" `

= 2.64 m

Distance covered by the wheel in 1 revolution = 2.64 m

Total distance = 19.8 km or 19800 m

∴ Number of revolutions taken by the wheel `=19800/2.64 = 7500`