Question

The diameter of a wheel of a car is 70 cm. How many revolutions will it make to travel 44 km?

Answer 1

Here , Diametre of circle
$= 70cm$
Radius of Circle
$= 35cm$
Area covered by cirlce in one round will be
$2 \times \pi \times r = 2 \times \pi \times 35$

Now , No. of Round covered will be
$total \: distance \: travelled \: by \: car \: \div distance \: travelled \: in \: one \: revolution \:$
$= 4400000cm \div (22 \div 7 \times 35 \times 2 )$

$= 20000 \: rounds$

.

Answer 2

diameter of wheel=70cm
radius=d/2=70/2=35cm
therefore circumference of a wheel=2πr
2×22/7×35=220cm
area covered by wheel in one revolution = circumference of a wheel=220cm
therefore number of revolution =4400000/220=20000