Question

The wheels of a car make 2500 revolutions in covering a distance of 4.95 km. Find the diameter of a wheel.

Answer 1

Distance = 4.95 km = 4.95 × 1000 × 100 cm

∴ Distance covered by the wheel in 1 revolution `= "Total distance covered"/"Number of revolutions"` 

`=(4.95xx1000xx100)/2500`

= 198 cm

Now,

Circumference of the wheel = 198 cm

⇒ 2πr = 198

`⇒ 2 ×22/7xx"r" = 198`

`=> "r" =(198xx7)/44` 

⇒ r = 31.5 cm

∴ Diameter of the wheel = 2r

= 2(31.5)

= 63 cm