The wheel of a lorry has radius 182 cm. The number of revolutions (approximately) per minute the lorry wheel will make is ______ (if the speed of the lorry is 66 km/h).
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 96.
We know that
Circumference of a circle = 2 × π × r
Now, according to the question
The circumference of of the wheel = 2 × 22/7 × 182 = 1144 cm
Here, the lorry can go 66 km in 60 min, then the lorry can cover in 1 min is = 66/60 = 1.1 km = 110000 cm
Now the wheel of the lorry makes the number of revolutions per minute is 110000/1144 = 96.15 or 96